OBJECTIVE To assess socio-demographic and behavioural characteristics of clients of female sex workers in Abidjan, and to determine their HIV prevalence and related risk factors. DESIGN A cross-sectional study among clients of female sex workers in Abidjan, Côte d'Ivoire. METHODS A trained interviewer approached clients leaving the room of a female sex worker and invited them for an interview using a structured questionnaire, and to provide a saliva sample. Saliva was tested for HIV antibodies by the GACELISA assay (Murex, Dartford, UK). RESULTS A total of 526 clients agreed to participate, and 423 (80.4%) provided a saliva sample. Reported condom use was very high, 92.7% said they always use condoms and 95.4% reported condom use during the visit preceding the interview. The overall HIV prevalence among the clients who provided a saliva sample was 13.4%. Older age and being married or cohabitating was significantly associated with HIV infection in multivariate analysis. CONCLUSIONS HIV prevalence appears to be relatively low, and condom use is high among clients of female sex workers in Abidjan. Existing HIV prevention efforts among female sex workers and among the general population should be sustained and reinforced.