Strauss-Kahn was called in by investigating magistrates two days earlier than expected and charged with the offence. His lawyers say the 62-year-old denies the charges and say they are going to appeal.
Strauss-Kahn has been placed under judicial control and has been forbidden from contacting defendants, plaintiffs, witnesses or the media.
His name came up as police were investigating a pimping operation that saw sex workers from brothels over the Belgian border being brought to France for orgies in high-class hotels in Lille and Paris.
Strauss-Kahn admits that he took part in some of these parties, one of which was said to involve women being flown to Washington to entertain him while he was still managing director of the IMF. But, through his lawyers, he has denied knowing the escorts were paid.
Using prostitutes is not illegal in France, but prosecutors are seeking proof that Strauss-Kahn was aware the parties were arranged by an organised pimping ring and paid for by other guests misusing company funds.
Several Lille-based businessmen and policemen have been accused of taking part in the ring. Strauss-Kahn told police he did not suspect the women were prostitutes because he was introduced to them by senior police officers.
Strauss-Kahn was implicated in the prostitution ring last year shortly after charges of sexual assault against a New York City hotel maid were dropped.