Introduction: Female sex is associated with better functional outcome in preclinical models of intracerebral hemorrhage (ICH). However, recovery is impaired after ischemic stroke as women age, relative to men, independent of stroke severity. We sought to define gender-age interactions for long-term neurological outcome after ICH across ethnicities. Methods: Clinical and radiographic data from subjects in the Ethnic/Racial Variations of Intracerebral Hemorrhage (ERICH; NS069763) and Genetic and Environmental Risk Factors for Hemorrhagic Stroke (GERFHS; NCT00930280) studies prior to January 2013 were used. Relationships between sex, age, and outcome in 473 black, 437 Hispanic, and 801 white subjects were evaluated after ICH using multivariable logistic regression analysis. Poor outcome was defined as modified Rankin ≥3 at 3 months after ICH. Age was modeled as a quadratic; gender-age interaction was modeled as centered cross-products to reduce collinearity. Results: Evidence of an interaction effect for gender and age on outcome at 3 months was found after ICH (p=0.054). The figure shows overlayed plots of the interaction between gender and age with regard to poor outcome. Women had lower risk of poor outcome at younger ages but higher risk at older ages. When testing this effect in different ethnicities, there was significant evidence of a gender-by-age interaction (p=0.005) within black patients. Conclusion: We found evidence of better outcomes in younger aged women than men, independent of comorbidities and severity of stroke. This trend reversed in elderly women. The gender-age interaction in outcome after ICH, seen especially in black subjects, may result from hormonal changes due to aging. Future studies to evaluate the impact of estrogen and progesterone in age/ethnic groups as a potential mediator of outcome are currently under design.