BackgroundFemale commercial sex workers (FCSWs) are considered a high-risk group for acquiring sexually transmitted diseases (STDs), yet the reported prevalence varies in studies around the world. The aim of this study was to determine the magnitude and associated factors of STDs among female sex workers.MethodsA community-based cross-sectional study was conducted among female sex workers in Finote Selam town. A total of 389 sex workers were studied using census method. Data were collected using an interview with structured questionnaires. The data were entered and analyzed by using SPSS version 20 software package.ResultsThe findings of this study showed that the overall prevalence of STDs was 20.6%. The reported prevalence of genital discharge, ulcer, and bubo was 15.9%, 15.2%, and 11.6%, respectively. In the multivariable logistic regression analysis, respondents who did not use a condom were about four times at higher risk of STDs than those who were using a condom consistently (adjusted odds ratio [AOR] = 4.07; 95% confidence interval [CI]: 1.812, 9.139). Respondents who experienced condom breakages were more than 12 times more likely to report STDs than those who never experienced condom breakages (AOR = 12.291, 95% CI: 5.701, 26.495).ConclusionThe findings of this study showed that one in five commercial sex workers in Finote Selam town had STDs. Sex without a condom and condom breakage during sexual intercourse showed a significant association with STDs. Therefore, the Woreda Health Office in collaboration with nongovernmental organizations in the area should work on safe sex promotion to enhance consistent condom use and reduce condom breakage through continuous education among commercial sex workers.