ABSTRACT: The socioeconomic status (SES) of women is increasingly considered an important factor for HIV/STI risk. The HIV/STI literature has largely focused on women's absolute levels of SES, and therefore, the importance of their SES relative to their male sexual partners remains understudied. This paper examines the association between women's relative SES and frequency of safer sex communication among heterosexual couples. A convenience sample of 342 couples (N?=?684) recruited in New York City was asked about frequency of discussions with their partner about the need to use male condoms, about HIV prevention, and about STI prevention in the previous 90 days. Differences between partners in education, income, employment, housing, and incarceration history were combined using principal component analysis to form an index of women's relative SES. Negative binomial regression models assessed associations between woman's relative SES and communication frequency controlling for age, sex, race, ethnicity, education, and relationship type using a generalized estimating equation framework. On average, participants had 2.5, 4.2, and 4.8 discussions regarding the need to use male condoms, about HIV prevention, and about STI prevention, respectively. A one standard deviation increase in a woman's relative SES score was associated with increased frequency of discussions about male condom use (adjusted rate ratio [aRR], 1.15; 95% confidence interval [CI], 1.03-1.29), about HIV prevention (aRR, 1.25; CI, 1.14-1.37), and about STI prevention (aRR, 1.29; CI, 1.18-1.41). Women's relative SES may be an important factor for sexual communication, and further research on its role in HIV/STI risk may uncover avenues for intervention.