Obtaining an upper secondary degree is highly esteemed for its economic and societal value. For students dropping out of school who return to education to earning an upper secondary degree (cf. high school—ISCED level 3)—termed “drop-in students” in this study—alternative pathways like “Second Chance Education” (SCE) have emerged. Empirical studies on these programs are limited, hindering theoretical progress and the understanding of drop-in students’ psychological and educational processes. To address this, the study aims to examine the profiles of drop-in students and the processes that may influence course completion rates in SCE. In doing so, it contributes to the growing body of research on SCE by investigating (1) student profiles and (2) the processes potentially affecting completion rates within a large sample of drop-in students.