By means of a theoretical model, this research investigated how the socioecological environment of university residence affects making friendship in the latter and students' academic success. The model contain four physical-environmental characteristics (distal variables): type of university residence (traditional, conventional), the location (outside or in the city center), and percentages of girls and of advantaged students. It also includes three social climate dimensions of university residence: Order and organization, Cohesion, and Open-mindedness (proximal variables, Bennacer, 2005). Making friendship and students' academic success were estimated, respectively, by following items: "Did you get your exams this year?" (No, In catching up, Yes) and "How many friends do you have in this residence?" (Five proposed answers, No friends to Many friends). By applying causal path analysis according to estimates maximum likelihood (n = 260 French students), a structural model was obtained on the socioecological determinants of making friendship in residence and of students' academic success. It accounts for 45 % and 81 % of the variance, respectively. Physical-environmental characteristics of university residence act directly on these criteria, and indirectly via the social climate dimensions of this residence which play an important mediating role. Making a lot of friends in the university residence inhibits students' academic success.