OBJECTIVE: To define risk factors for gonococcal infection. METHODS: A case-control study comparing 200 gonorrhoea cases with 400 patients with non-gonococcal genitourinary infections and 400 patients with various skin diseases, all of them attending City Department for Skin and Venereal Diseases In Belgrade (Yugoslavia) from October 1993 to December 1994. RESULTS: According to multivariate logistic regression analysis the following factors were significantly related to gonorrhoea in men: education level, sexual contact same day as meeting, condom use, history of prior gonorrhoea, and casual and/or new sex partner in the past month. Age, sexual contact same day as meeting, number of partners in the past year, and frequency of sexual intercourse in the past month were independently, significantly related to gonorrhoea in women. Also, in females, gonorrhoea was significantly more frequent in industrial workers and supported people. CONCLUSION: Since sexual behaviour, low education level, younger ages, and low socioeconomic status were found to be related to gonococcal infection, health education at early age seems to be the most appropriate means of altering high risk behaviour.