The importance of gender within HIV/STI prevention has become widely recognized. However, gender ideologies associated with vulnerability to HIV/STI are often examined and addressed without sufficient attention to the larger socioeconomic context within which they arise and evolve. We conducted a cross-sectional survey with 155 female, African-American adolescents recruited from two health clinics in Baltimore, Maryland. Multivariate logistic regression was utilized to assess the relationships between HIV/STI vulnerability resulting from male partner concurrency, adherence to traditional female gender norms, using a measure of hyperfemininity, and perceived socioeconomic opportunity structures. The likelihood of reported partner concurrency increased significantly among participants reporting higher levels of hyperfemininity (OR = 2.08; 95%CI = 1.01-4.30). Hyperfeminine thinking and behavior was significantly lower in the context of higher perceived socioeconomic opportunity structures (OR = 0.87; 95%CI = 0.79-0.95). Interventions seeking to promote gender equity and reduce HIV/STI may be more effective when the socioeconomic context of gender ideologies is assessed and addressed. Programs and policies to increase educational and professional opportunity structures, particularly among marginalized communities, should be actively integrated into HIV/STI prevention planning.