DIY tattoos pose "very serious dangers", according to the Local Government Association (LGA).
The LGA, which represents councils in England and Wales, is warning that using cheap kits online could lead to skin infections, blood poisoning and scarring.
Echoing a similar call in 2010, it's also warning about illegal, rogue artists known as scratchers.
Full, working tattoo kits are being sold online for as little as £24.
Jay Hutton, a professional tattoo artist who appears on E4 show Tattoo Fixers, told Newsbeat: "I think it's a major problem. The main reason people go to scratchers is because they do it cheap.
"Tattoos aren't cheap and cheap tattoos aren't good.
"The quality if the [cheap] machines is terrible. That's why quality machines are expensive.
"A lot of people buying them online don't have the right sterilisation equipment either.
"The risk of what you can catch is so high. It can be life threatening really. Something needs to be done about it."
Using sub-standard equipment to get tattoos can lead to blistering or irritation of the skin but can also have more serious health complications.
The warning also suggests that going to unregistered artists could result in infections like MRSA and said it was "concerned about the very serious dangers of Hepatitis, HIV, skin infections as well as permanent scarring that can arise from illegal tattoos".
The LGA says celebrities posting images of tattoos online are encouraging people to get them.
Ed Sheeran was recently criticised for a tattoo of a lion he got on his chest to mark his three sold out shows at Wembley stadium.
He responded on Twitter saying: "It's not the first weird tattoo I've got and it won't be the last."
Tattoo artist Jay doesn't think celebrity influence is an problem.
He said: "I think it's a personal issue. Everyone is entitled to get a tattoo. It's basically who you get tattooed by and where you get it done.
"It comes down to research. I understand that some people can't afford it - but if you can't afford, it you can't afford it .
"Would you rather have no tattoo and not afford it or would you rather risk catching some horrible disease for £20?"
Peter Flemming from the LGA added: "What we're finding is that increasing numbers of illegal and unlicensed tattooists are doing this.
"We're asking for people to understand the risks associated with tattooing and understand the law that goes with it."
The law states that it's illegal to work as a tattooist without registering with a local council.
It's also against the law to tattoo someone under the age of 18, even with their parents' consent.
Tattooists who ignore the law can be prosecuted under health and safety legislation and can face a fine of up to £20,000 or a jail sentence.