Background: Studies have identified high prevalence of depression among people living with HIV/AIDS, but only few studies have looked into this association in this environment. It is desirable to identity factors associated with depression among people living with HIV/AIDS. Aims and objectives: The study is aimed at looking at the prevalence of depression among people living with HIV/AIDS. The objectives were to determine the prevalence of major depression among HIV/AIDS patients attending an Out-patient clinic at the OOUTH, Sagamu and the associated socio-demographic, psychosocial and clinical variables. Method: One hundred and thirty subjects living with HIV/AIDS were recruited for the study. They were assessed with a socio-demographic questionnaire designed by the researcher, and they also had a clinical interview with the depression module of the Structured Clinical Interview Schedule for Axis 1 DSM IV disorders (SCID). The diagnosis was made according to the DSM IV criteria. Severity of depression, for those meeting the diagnosis was assessed with the Hamilton Depression Rating Scale. ` Results: The prevalence of depression among subjects living with HIV/AIDS was 23.1% and was higher than figures reported in the general population studies in Nigeria. Depression was significantly associated with being female and having suicidal thoughts or attempt. There was no association between marital status, disclosure of status, use of anti-retroviral and duration of diagnosis. Conclusion: People living HIV/AIDS are predisposed to depression and an appropriate mental health intervention programme will be necessary as part of National programme for them.