This study examined gender differences in self-regulation in the fall and spring of kindergarten and their connection to gender differences in 5 areas of early achievement: applied problems (math), general knowledge, letter-word identification, expressive vocabulary, and sound awareness. Behavioral self-regulation was measured using both an objective direct measure (N = 268; Head-Toes-Knees-Shoulders task) and, for a subsample of children, a teacher report of classroom self-regulatory behavior (n = 156; Child Behavior Rating Scale). Results showed that girls outperformed boys in both assessments. Although gender differences in self-regulation were clear, no significant gender differences were found on the 5 academic achievement outcomes, as measured by the Woodcock-Johnson III Tests of Achievement. Self-regulation consistently predicted math and sound awareness, although links were stronger with the direct measure as compared with teacher reports. Implications for understanding the role of gender and self-regulation in early and later academic achievement and the role of self-regulation in particular areas of achievement are discussed. (Contains 2 figures and 4 tables.)