A person generally commits the crime of prostitution by engaging in sexual contact or offering to engage in sexual contact in exchange for money or other consideration.

It is also a criminal offense to solicit (on a person's own behalf, or on behalf of another person), promote, or compel prostitution. For example, most states have laws that make it illegal to buy, sell, or profit from prostitution—which is generally the business of pimps and other human traffickers—known as pimping, pandering, procuring, soliciting, promoting, or compelling prostitution.

Prostitution laws vary from state to state and are generally located in a state’s statutes—often in the penal or criminal code.

In Illinois, prostitution is illegal under the Illinois Compiled Statutes, specifically 720 ILCS 5/11-14, which defines the crime of prostitution as knowingly performing, offering, or agreeing to perform any act of sexual penetration or touching of the sex organs for anything of value. The law also criminalizes the purchase of sexual services. Solicitation of a sexual act is also illegal under 720 ILCS 5/11-14.1, and it is a separate offense to solicit a sexual act for money or other consideration. Additionally, promoting prostitution, which includes pimping, pandering, and profiting from the prostitution of another, is prohibited under 720 ILCS 5/11-14.3. The severity of the charges can range from a Class A misdemeanor for a first offense of prostitution to a Class 4 felony for promoting prostitution, with potential penalties including fines and imprisonment. The state may also impose stricter penalties for prostitution-related offenses involving minors or if the offense occurs near a school or family residence.