China has experienced a surge in internal migration during the past decade, and migrant populations have been identified as a high-risk group for HIV and other sexually transmitted infections (STIs). Young female migrants often find employment in entertainment venues (bars, karaoke parlors, and massage parlors) located in metropolitan cities, and sex work transactions frequently occur in these venues. We examined factors associated with risk for HIV, other STIs, and reproductive health challenges in a cross-sectional study of 358 young female migrants, ages 18-29, working in entertainment venues in a rapidly growing urban city in China. Results indicate high levels of behavioral risk for HIV and other STIs, low rates of HIV testing, and high prevalence of problem drinking and mental health problems, including recent depression symptoms and suicidal ideation. Factors associated with increased STIs and genitourinary tract infections included commercial sex work, early sexual debut, abortion history, illicit drug use, and anxiety. Factors associated with increased HIV testing included employment in an affluent entertainment venue, education level, knowledge about where to obtain free HIV tests, condom use, and general HIV/AIDS knowledge. Findings of this study highlight the insufficient coverage of current public health services to female migrants working in entertainment venues and call for more assertive prevention interventions to mitigate risk for sexual, reproductive, behavioral, and mental health problems in this mobile population.