Impulsivity is a trait characteristic that is associated with sexual risk behavior. We examined correlates of impulsivity among 602 female sex workers (FSWs) enrolled in a sexual risk reduction intervention in Mexico (2016–2020). Impulsivity was positively associated with condomless sex with clients. Higher levels of impulsivity were associated with greater use of alcohol and heavy drugs, use of illicit drugs with clients, sexual/physical abuse history, and clinical depression. Global public health policy that supports free substance abuse treatment in combination with psychotherapeutic treatments (e.g. regulation management skills) and behavioral-focused therapy may help to reduce HIV/STI incidence in this vulnerable population. [ABSTRACT FROM AUTHOR]