Introduction: Intrafamilial relationships are the interactions and bonds established between family members. During adolescence, they are essential for achieving comprehensive development. Together with strengths, their balance provides each individual with the ability to act responsibly within their family and social environment. When these relationships and strengths are well established, they contribute to overall well-being. It is important to know whether there are differences between men and women with regard to these variables. Objective: To compare gender differences in intrafamilial relationships and strengths in high school students. Method: A cross-sectional correlational study was conducted with 315 students from a public university in Mexico. The revised short version of the intrafamilial relationship assessment scale and the adolescent strengths assessment scale were applied. Mean comparisons were made using Student's t-test for independent samples. Results: No statistically significant differences were found between males and females in intrafamilial relationships. In terms of external strengths, differences were detected in maternal support t(313) = -2.04, p = .042, d = -0.23 and maternal supervision t(313) = -3.60, p < .001, d = -0.42 in favor of women. Meanwhile, in internal strengths, differences were found in resistance to pressure, t(313) = 2.79, p = .006, d = 0.32, with higher means in men, and expression of anger, t(313) = -3.81, p < .001, d = -0.44; and school expectations, t(313) = -2.51, p = .013, d = -0.29, with higher scores in women. Discussion: The results show that there are differences between the strengths related to male and female adolescents that should be taken into account in interventions.