This study determined the prevalence of depression and associated factors, among patients attending chronic disease clinics in Southwest Trinidad. This was a cross- sectional survey using a sample of consecutive patients at four large clinics. To determine the presence of depression, an interviewer applied modified Zung Scale was validated. The modified Zung scale, at the cut-off index of 60, has a sensitivity of 60% and a specificity of 94%. Seven hundred and thirty-four completed questionnaires were received, a response rate of 76%. The patients were primarily Indo-Trinidadian (70%), over 50 years (76.4%) and female (72.3%). The prevalence of depression was 28.3%. There were statistically significant differences in the level of depression by age, gender, educational level achieved and occupation (p < 0.05). There were also statistically significant differences in the level of depression by the number of presenting complaints, the number of chronic diseases, the presence of arthritis, the presence of diabetes mellitus with another chronic disease and the presence of ischaemic heart disease (p < 0.05). No significant differences were found with respect to ethnicity (p = 0.97) or the presence of diabetes mellitus by itself (p = 0.34). Results of logistic regression indicate that the independent predictors of depression (p < 0.05) were the level of education achieved, those with higher levels of education had less depression; the number of presenting complaints, those with more presenting complaints were more likely to be depressed and the presence of arthritis and female gender. It is imperative that policy be developed to address the mental health problems of patients attending these chronic disease clinics.