Introduction: The working conditions and violence against sex workers has been linked to increasing rates of sexual transmitted diseases. But there are also other diseases that affect their mental health. Objectives: To determine the magnitude of depressive symptoms and associated factors in sex workers. Design: Crossanalytic study. Setting: Health Centre of reference for the prevention and control of sexually transmitted infections. Participants: Sex workers. Interventions: Beck test was applied to 117 sex workers attended between May and June 2010 in order to measure depressive symptoms as well as a survey to determine socio-demographic and social (physical abuse, psychological and sexual labor and harmful habits: alcohol and drug abuse) factors, risky sexual behavior and job characteristics (age at onset, years of work, job satisfaction). Main outcome measures: Percentage of depressiv...