Disorganization refers to the difficulty that some learners have developing an organized approach to studying. The aim of the present study was to explore antecedents and consequences of disorganization, and individual differences in how disorganization occurs. A questionnaire was administered to 177 French first-year students enrolled on STEM courses. Results of multiple regression analysis showed that social integration and performance-avoidance goals are negative predictors of disorganization, and weak prior achievement a positive one. A cluster analysis revealed that disorganization can be associated with either a large or a small amount of time spent studying. Students also differed from one another on engagement-related variables according to time spent studying. The article argues that disorganization may be associated with engagement when students undergo the transition to higher education. The conclusion outlines some practical implications for teaching, and proposes directions for future research.