In Europe during the Middle Ages prostitution was not merely tolerated but was protected, licensed, and regulated by law, and it constituted a large source of public revenue. Public brothels, or places of prostitution, on a large scale were established in large cities throughout Europe.
Stricter controls were imposed with the outbreak of an epidemic of venereal disease in the 16th century and with the advent of new ideas of sexual morality brought in with the Reformation. Brothels were closed throughout Europe, and when disease continued to claim victims, regulations became even more stringent. Some cities passed laws requiring periodic medical inspection, but these had little effect.

International cooperation to stamp out the traffic in women for the purpose of prostitution began in 1899. In 1921 the League of Nations established the Committee on the Traffic in Women and Children, and in 1949 the United Nations General Assembly adopted a convention for the suppression of prostitution.

In the United States prostitution flourished in most cities and was virtually uncontrolled until the passage of the Mann Act in 1910, which prohibited interstate transportation of women for immoral purposes. By 1915 nearly all states had passed laws banning brothels and regulating the profits of prostitution.

In most large Western cities prostitution is tolerated. The police there are more concerned with regulating the crimes associated with prostitution, which are often controlled by organized crime syndicates.

Throughout Asia prostitution continues to flourish openly, though Chinese officials maintain that it no longer exists in that country. In most Eastern countries prostitution is an urban problem, but in India a majority of prostitutes are in rural areas.

Female prostitutes are often economically disadvantaged and are usually unmarried and lack skills to support themselves. Many are drawn at an early age into the subculture of prostitution and associated crime. Health hazards to prostitutes include acquired immunodeficiency syndrome (AIDS), venereal diseases, and, in some subcultures, drug abuse. (See also Drugs, "Drug Abuse"; Sexually Transmitted Disease.)

Male prostitution has received less public attention in most cultures. Heterosexual male prostitution--males hired by or for females--is uncommon. Homosexual male prostitution, however, has become increasingly common, in large cities in particular, in the 20th century.