Background: Evidence for the effectiveness of the selection of medical students is weak. This study aimed to examine the added value of a two-step selection procedure (first step non-academic, second step academic tests) to a pre-university GPA-based lottery procedure. Because previous research has suggested that participation in selection (regardless of the outcome) is a predictor of study success, this study is the first to include students who initially applied for selection, then refrained from (actively) participating in selection and were eventually admitted through lottery. Methods: Bachelor completion and dropout rates of selected (n = 416) and lottery-admitted students from four cohorts (2006-2009) were compared using logistic regression analysis. Four groups of lottery-admitted students were distinguished: students who were rejected after step 2 (n = 57), were rejected after step 1 (n = 169), withdrew during selection step 1 (n = 42) and students who only applied for lottery (n = 366). Covariates included gender, age, pre-university GPA and cohort. Results: There was a significant association between admission group and obtaining a bachelor degree in three years. Selected students were more likely to obtain a bachelor degree within three years (64.2% versus 51.6%; OR = 1.7) or four years (81.5% versus 74.3%; OR = 1.6) than students who only applied to a lottery (p < 0.05); selected students also seemed more likely to obtain all Year-1 course credits than students who withdrew during step 1 (40.4% versus 21.4%; OR = 2.3; p < 0.05). We found no significant association between dropout and admission groups. Students rejected at step 1 or 2 did not perform significantly different from selected students on any of the outcome measures. Conclusions: The findings indicated that students at risk for study delay in the preclinical phase in our context were more likely to refrain from applying to a demanding selection procedure when a less demanding alternative was available. We found no significant associations between the non-academic and academic selection steps and bachelor completion and dropout rates. These findings suggest that the presence of the selection was more important than these specific selection components. In follow-up research, we plan to investigate the associations between the admission groups and outcome measures in the clinical phase.