The number of prostitutes on streets in the city has dropped from 250 to about 50, the police figures showed.
Police said the fall was caused by "improved drop-in centres and outreach" and "effective one-day courses" had cut reoffending by men using prostitutes.
But charity group Prostitute Outreach Workers said prostitution had not disappeared but moved off the streets.
Sgt Neil Radford of the force's street prostitution section said since 2004 more than 840 men in Nottingham had taken part in the "Change" course, which was designed to tackle kerb-crawling. Only 2.5% of those men are know to have reoffended, he said.
The rehabilitation programme is offered to men who have been caught buying sex from prostitutes. They are not charged but are given a police caution.
Sgt Radford said he believed it was possible to "eradicate" prostitution from Nottingham streets.
But Daniella Scotece, a Prostitute Outreach Workers project manager in the city, said: "The complex issues of drug addiction and mental health do not disappear.
"They work from a crack house and are not roaming the street - others issues such as mental health problems and homelessness are still there."
She said often the women used mobile phones and computers to arrange custom.
Ms Scotece said an increase in the number of anti-social behaviour orders (asbos) handed out to prostitutes meant they were less visible on the streets but were working from other locations.
Street prostitution in Nottingham has decreased by 80% over the past decade, according to Nottinghamshire Police.