Background: Depression is a growing health issue in both developed and developing countries. General unawareness at the population level, lack of training among health care providers and scarcity of resources including treatment opportunities may conceal the real burden of depression in developing countries, and more epidemiological studies on its prevalence and risk factors are critically needed. Aim: This study reports the prevalence of depression and its associated risk factors among female garment factory workers in Bangladesh - a major supplier country of clothes for the Western market. This research should generate useful evidence for national and international stakeholders who have an interest in improving health, safety and well-being of outsourced factory workers. Methods: A survey was conducted on a sample of 600 lower socio-economic status working women including garment workers. This survey collected data on demographic and health profile of these workers. The primary outcome was depression as measured by Patient Health Questionnaire 9. It also obtained data on traumatic life events and post-traumatic stress disorder. Results: The prevalence of depression was 23.5%: 20.9% among garment workers and 26.4% among others. Part-time employment (odds ratio-OR): 2.36, 95% confidence interval (95% CI): 1.01-5.51), chronic pain (OR: 1.67, 95% CI: 1.01-2.78), two or more traumatic life events (OR: 6.43, 95% CI: 2.85-14.55) and dysuria (OR: 2.50, 95% CI: 1.02-6.15) were found to be significantly associated with depression among these workers in multivariate regression model. Depression prevalene lowered by 11% among these workers for every additional monthly earning of 1,000taka (US$12). Conclusion: Depression is a multifaceted health issue with many personal, social, economic and health determinants and consequences. This study demonstrates that the prevalence of moderate-to-severe depression among working women in Bangladesh is quite high. Prevention and treatment of depression in developing countries and societies can reduce suffering, lower incidence of suicide, and prevent economic loss. Creating awareness on outsourced workers' poor mental health may help in developing initiatives to protect and preserve their well-being.