Female sex workers are degraded by society all over the world. Most of them suffered from depression and different sorts of mental disorders are developed among them. To find out the psychiatric disorders among female sex worker seeking medical treatment in a STI/RTI treatment centre run by Non Governmental Organization (NGO), Dhaka. This cross-sectional study was conducted at outdoor treatment centre of an NGO in Dhaka city from January 2019 to December 2019 over a period of one year. Fifty female sex workers were selected for this study. The mean age of the respondents was 33.2 ± 7.9 years within the range of 21 – 47 years. Almost two-thirds of the respondents just completed their primary education and 22.0% of the respondents were illiterate. Maximum respondents were either single or live away from family. Only 32.0% of the respondents lived with their respective husbands. More than half of the respondents had no good relationship with their respective husbands. The average monthly income was 235 US Dollar (USD). Income varied from 47 USD to 588 USD. About 36% of respondents had family members more than 04 persons. Family members varied from 01 to 07. As a sex partner, most of the respondents preferred males and the most preferable route was mouth. 38.0% of the respondents used barrier and 18.0% of the respondents had a selective client. According to DSM-5, Major Depressive Disorders was observed in 62% respondents, Substance/medication-induced psychotic disorder 18%, anti-social personality disorder was observed in 08% respondents and Histrionic personality disorder was observed in 12.0% respondents. The prevalence of Psychiatric morbidities is an under attended problem in Bangladesh. To the author’s best knowledge this is the first psychiatrist approach to female sex workers in Bangladesh .Further large scale extensive studies would be necessary for better visualization of the extent of the issue.