Dozens of cars were parked outside. Crowds thronged the pavement, desperate to get through the metal gates.
In the courtyard women were filling plastic bottles and jerry cans with water blessed by the imam.
As I took off my shoes, I noticed a marble plaque on the wall:
"There is no illness which Allah cannot cure".
Inside, huddles of families were camped out on sofas.
There were many tearful faces. Men paced up and down. It might have been an ordinary hospital waiting room until a girl started shrieking and contorting.
A man scooped her up and carried her off into a room off the landing.
Spine-chilling yells came from behind the frosted glass door but nobody turned a hair. Gradually they were stifled by incantations from the Koran.
Most of the patients here are young women and many have suffered breakdowns after being forced into marriage. They are brought to be exorcised and turned into Chechen-style Stepford Wives.
The Centre for Islamic Medicine is an imposing red brick mansion near the centre of Grozny.
It was once the headquarters of the Chechen warlord Shamil Basayev - Russia's number one enemy and the man who masterminded the school hostage siege in Beslan in 2004.
Like many buildings in the Chechen capital, the centre has been expensively renovated.
Two wars for independence from Russia reduced Grozny to rubble.
Turning a blind eye
Since the ceasefire, the Kremlin has bankrolled a reconstruction programme and the main street, renamed Putin Avenue, is now unrecognisable with its pavement cafes, designer shops and sushi bars.
But Ramzan Kadyrov, President of this once-rebel republic in southern Russia, has also built an extensive Muslim infrastructure. It includes one of the world's biggest mosques, religious schools and an Islamic university.
The medical centre is run by Kadyrov's personal doctor. In its first year, it claimed to have cured more than 60,000 people suffering from "psycho-neurological diseases".
After 15 years of fighting, there is no shortage of traumatised people in Chechnya.
Mr Kadyrov once fought the Russians but is now their key ally in keeping a lid on the insurgency in the North Caucasus.
In return, the Kremlin turns a blind eye to allegations of torture and violence committed by his personal militia. Kadyrov routinely denies these.
His officials also deny that the Chechen leader puts Islamic law above Russian law.
But in practice Kadyrov has a free hand to impose his own version of what he calls "traditional Chechen Islam".
Imams deemed disloyal to the regime are summarily dismissed. Gangs of men dressed in black, from his newly-opened Centre for Spiritual and Moral Education, roam the streets lecturing passers-by about the evils of alcohol and the right kind of Islam.
Young men accused of siding with rebel fighters have disappeared from their beds at night never to be seen again. Their relatives have been arrested and their homes burned to the ground.
Women too are targeted by Mr Kadyrov's reforms.
In 2007, in violation of Russian law, he issued an edict banning women and girls without a headscarf from schools, universities and other public buildings.
Since June, unidentified men with paintball guns have driven round the centre of Grozny shooting at girls with uncovered heads.
On state television, Mr Kadyrov said he did not know who was responsible for the attacks but added: "When I find them, I will express my gratitude."
When I met the Chechen president in the capital's football stadium last summer, he told me: "Women are so much more interesting when they are covered up."
Officials nearby smiled awkwardly as Kadyrov boasted that Chechen men can take "second, third and fourth wives" and that polygamy, illegal in Russia, was the best way to revive his war-ravaged republic.
According to some estimates, one in five Chechen marriages begins when a girl is snatched off the street and forced into a car by her future groom and his accomplices. The internet is full of videos of these "bride stealings" set to romantic music.
More often than not, the girl is pressured into marrying her kidnapper to preserve family honour and avoid triggering a blood feud. Some are resigned to their fate and make a surprising success of their marriages.
For others, that is far from the case.
Blindfolded and beaten
Lipkhan Bazaeva, who runs an organisation called Women's Dignity, says brides are often brought in by mothers-in-law who believe the girl is possessed by evil spirits or "genies".
"Just imagine - her son has stolen a girl he liked and married her. What they want is a nice, quiet, hard-working woman in the house, not someone who's feeling down from the moment she wakes up and who's hysterical in the evening. So they take them to the mullah."
Mullah Mairbek Yusupov is a small bearded man dressed in a green surgeon-style top and skull-cap. He appeared pleasant enough to me, softly spoken, until I saw him at work.
The patient was lying blindfolded on her back, wearing a long, flowery robe. Mairbek began yelling verses from the Koran into her ear and beating her with a short stick.
"She feels no pain," he said. "We beat the genie and not the patient."
The woman, probably in her early twenties, was writhing on the bed: "Shut up! Leave me alone," she growled.
Mairbek claimed this strange voice belonged to the genie possessing her. He shouted back: "Take your claws out of this woman. Aren't you ashamed? Go on! Leave her body like you did last time, through her toe."
With a deadpan expression, Mairbek explained that the genie inside the girl was 340 years old.
He was not a Muslim - he was a Russian man called Andrei and he had fallen in love with his victim.
The genie was so jealous that he made her leave her husband. "It was a tough case," he added. This was already the seventh time he had treated this patient.
Later I spoke to the girl's aunt, who had also watched the exorcism. She said her niece was stolen at the age of 16 and had since been through two divorces.
"She wants to be alone all the time," she sighed. "She doesn't want to talk or see anyone and nothing makes her happy."
The girl's despairing family were hoping doctors at the Centre could turn her into an obedient wife so they could marry her off again.
A few days later I met Marryat, another patient. She had been stolen for marriage but found her kidnapper was already married to somebody else. Now she is convinced that his first wife put a curse on her in the form of two genies.
When she split from her husband, Marryat had to give up her baby son.
According to Chechen traditions, after divorce children are raised by the husband and in-laws. Former wives almost never get custody despite their rights under Russian law. It is considered shameful to go to court.
I asked Mairbek if he always blamed the genies for marital breakdown. Perhaps, I suggested, some women are traumatised by being abducted and forced into marriage or by losing their children?
Mairbek was dismissive.
"We have so many young girls with these problems. I had a patient today whose genie tells her she should divorce, that her husband doesn't love her; that she shouldn't stay in an unhappy marriage for the sake of the children."
"But that's just the genie trying to get its own way and we have to put a stop to that," he said.
Whatever I felt about his methods, Mairbek did not strike me as a sadistic man.
I was struck by the readiness of patients and relatives alike to accept the treatment, and even to come back for more.
The therapy is a way of making them accept, or at least deal with, what has happened. But, it is most of all, an expression of their powerlessness.
The tragedy of these women is that they have nowhere else to go.
This World: Stolen Brides will be broadcast on Wednesday, 11 August 2010 at 1900 BST on BBC Two. Or catch up afterwards on BBC iPlayer