BACKGROUND: Depression is the most common psychiatric disorder among the elderly which can manifest as major or minor depression. The community-based studies have revealed that the prevalence of depression in geriatric population in India varies between 13% and 25%. In spite of quantum of this problem there are very few studies from India investigating geriatric depression and its associated risk factors. This study aimed to establish the prevalence, sociodemographic correlates and factors associated with geriatric depression in urban slum and rural communities in Chennai. METHODS: This study was done as a cross sectional study in the urban and rural field practice areas of ACS Medical College and Hospital among 60 years and above age group by house to house survey method using Geriatric Depression Scale during July and August 2011.All the houses in the urban and rural field practice areas were surveyed and those who fulfilled the eligibility criteria were interviewed after getting informed consent. The results were expressed in percentages and chi-square test was done to find out the association. RESULTS: Totally 173 study participants were interviewed and the prevalence was found to be 41.1% and 45.8% in urban and rural communities respectively. Geriatric depression is significantly associated with female sex, living without spouse, illiteracy, time spent with children and grand children and dietary habits in both communities but money dependence and health problems were strongly associated with depression in urban community. CONCLUSION: The prevalence of depression in the elderly population in our study was moderately high in both areas and a cause of concern. KEY WORDS: Geriatric depression, socio-demographic factors, money dependence, Geriatric depression score.