The purpose of this study was to investigate a large number of determinants of sport dropout among French adolescents, in order to reveal proximal and distal factors of dropout. 261 current and 106 dropout athletes (M = 14.6) participated to the study. The data were collected by a questionnaire assessing demographic information, athletes’ perceptions on their experience, their parents, teammates and coach. t-tests revealed that current and former athletes were distinct on numerous variables. A discriminant function analysis showed three proximal predictors of sport dropout (perceived value of the activity, satisfaction, parents’ investment). Subsequent regression analyses showed that perceived value was positively predicted by perceived competence, the value of the activity for teammates, coach’s investment, and negatively by conflicts of interest and goal conflict with teammates; satisfaction was positively predicted by the coach’s mastery climate, but negatively predicted by conflicts of interest and goal conflict with teammates and with the coach; parents investment was negatively predicted by the goal conflicts with them. This study permitted to discriminate between proximal and more distal psychological antecedents of the dropout behaviour. It brings information relative to the possible targets of interventions aiming at preventing dropout from organized sport.