Prostitution is illegal, punishable by up to seven years in jail
Uganda's government has banned a workshop for prostitutes scheduled to start on Wednesday in Entebbe.
"We don't take any delight at all in the idea that prostitutes are coming together to devise ways of spreading their vice," the ethics minister said.
Prostitution is illegal in Uganda although sex workers operate freely in the capital, Kampala.
The conference organisers from the US, Kenya and Uganda wanted participants to be aware of their human rights.
"We call it a vice because in Uganda it's an illegality which is punishable by seven years [in jail]," Ethics Minister Nsaba Buturo said when he announced the ban last week.
"Uganda's made a decision that homosexuality, prostitution and those things are not our way of life. Anyone who violates them really will deserve what they get," he added.
The BBC's Joshua Mmali in Kampala says according to an invitation letter shown to journalists, participants had been invited from across the East African region.
They were to have all their flights and living expenses paid for during the four-day gathering organised by the Open Society Institute, the Open Society Initiative for East Africa and Ugandan-based women's group Akina Mama wa Africa.
Last year, ahead of the Commonwealth leaders' meeting in Kampala special zones were set up to control the activities of commercial sex workers.
An editorial in the state-run New Vision newspaper has called for a debate on whether prostitution should be regulated.
"Prostitutes are everywhere; in pubs and hotels, on streets in brothels, massage parlours and strip bars," it said.
"If the police were to enforce the law, probably they would not do any other work.
"This would not end the practice, but only increase the number of criminals and government spending."