Pre-kindergarten (Pre-K) improves the school readiness of all children, but less is known about whether associations between enrollment in Pre-K and different indicators of social–emotional and executive functioning (EF) skills are sustained as children move into and across elementary school. The current study examines associations between enrollment in the Boston Public Schools (BPS) Pre-K program and children's (N = 508) social–emotional, approaches to learning, and EF skills at both the start and end of kindergarten. Results from multilevel regression models revealed that children who enrolled in BPS Pre-K started kindergarten with lower internalizing behaviors and higher levels of task orientation than their peers. These associations, however, were not sustained through the end of kindergarten. Instead, there were emerging associations between BPS Pre-K and two dimensions of EF—working memory and inhibitory control—at the end of the kindergarten year. The results were robust to different model specifications, including inverse probability of treatment weighting. Taken together, the results highlight the importance of examining links between high-quality Pre-K and different indicators of children's social–emotional and EF skills across time in order to provide a more complete picture of how Pre-K supports different types of skills across time.