There are calls for a committee to handle complaints about Welsh Assembly members rather than an individual.
Sir Roderick Evans resigned as standards commissioner after AM Neil McEvoy claimed secret recordings of him showed sexism and bias.
Eleven charities and think tanks say a more robust system is needed to cope with "issues seen in today's politics".
Writing to the assembly's presiding officer, they say the commissioner role should be replaced by a new panel.
Douglas Bain was appointed acting standards commissioner on Wednesday, following Sir Roderick's resignation.
The letter to presiding officer Elin Jones is signed by organisations including the Women's Equality Network, Electoral Reform Society, Welsh Women's Aid, Disability Wales and the Institute of Welsh Affairs,
They say in the letter that they have long been concerned that the role of the commissioner "has not been robust enough to provide a meaningful response to the issues seen in today's politics".
"The events of the past few days have highlighted even further to us that the role of Standards Commissioner needs urgent reform," they add.
Last year, Sir Roderick was criticised when he ruled that a video made by the then-UKIP AM Gareth Bennett portraying Labour member Joyce Watson's head on a barmaid's body was not sexist.
Mr Bain was called in to re-investigate the matter and recommended Mr Bennett be suspended from the assembly for a week, ruling that he had "demeaned" Ms Watson.
The eleven organisations argue that a panel rather than a commissioner would "ensure experience and expertise in dealing with sexual harassment cases as well as a wide range of other issues".
"It is clear that one person cannot have the expertise required to cover a range of fields," they say.
They also call for specialist support to be offered to the panel as required, along with increased sanctions to deal with abuse and harassment and powers to investigate incidents which happened more than a year ago.
A spokesperson for the Assembly Commission, which runs the institution, said the remit of the standards commissioner's office was a matter for the assembly's standards committee.
"The committee is reviewing the code of conduct for assembly members and, as part of this, it will be considering the role and remit of the standards commissioner," the spokesperson said.
"The committee will be keen to engage with a range of organisations to benefit from their expertise in this area."