AbstractOne hundred and thirty‐seven fourth‐grade pupils participated in a follow‐up study of the effect of school‐entrance age on academic achievement and social‐emotional functioning. The sample included 73 oldest pupils, born in the months of January to March, and 64 youngest pupils, born in October to December of the same calendar year. Results indicated that differences between the two groups in academic and social‐emotional measures, found when the subjects were in first grade, persisted in part to the fourth grade. The youngest subjects continued to score lowest in mathematics and in oral and silent reading comprehension; they were slower readers; and they had higher trait anxiety scores. In addition, the differences between the groups in oral and silent reading comprehension performance were found to increase ove