The objective of the study was to identify risk factors associated with sexually transmitted diseases (STDs) among rural-to-urban migrants in Beijing in 2002. Migrants with STDs consisted of 432 migrants who sought STD care in two public STD clinics. Migrants without STDs included 892 migrants recruited from 10 occupational clusters. Multiple logistic regression was used for data analysis. Compared to migrants without STDs, migrants with STDs were more likely to report having engaged in commercial sex (selling or buying sex) (odds ratio [OR] = 2.70, 95% confidence interval [CI]: 1.71-4.25), multiple sex partners in the previous month (OR = 6.50, 95% CI: 3.73-11.32) and higher perceived HIV-related stigma (OR = 1.89, 95% CI: 1.30-2.75). Being a migrant with an STD was also associated with female gender (OR = 4.10, 95% CI: 2.89-5.82), higher education (OR = 2.92, 95% CI: 1.40-6.06), and higher monthly salary (OR = 1.68. 95% CI: 1.23-2.29). Migrants with STDs visited their hometowns more frequently and had more stable jobs than migrants without STDs. Approximately 10% of the migrants with STDs and 7.7% of the migrants without STDs always used condoms. This study suggests that among migrants, acquisition of an STD is associated with higher participation in risk behaviors as would be expected, but also with higher perceived stigma, education, stable jobs, salary, and with female gender. Appropriate behavioral intervention programs are advocated to reduce the risk and stigma among the special population.