This article presents a summary of results from a Swiss nationwide empirical study of the determinants of grade retention, its effects on learning, and its social and emotional consequences. Results show that the decision for grade retention does not rest only on the pupil’s actual academic performance but also on the teacher’s attitudes and evaluations. With regard to improvement in learning, the study yields contrasting shortand medium-term results: They are positive in the case of same-grade comparisons and negative when same-age comparisons are applied. However, globally, the effectiveness of grade retention is rather unsatisfactory, particularly when one considers its long-term consequences, although there is no evidence of negative social or emotional consequences. It is nevertheless suggested that grade retention should be avoided at the primary school level.