This study examined the longitudinal associations of emotional regulation and school readiness among Chinese kindergarten children. Data were collected from 523 children (mean age at time 1 = 52.42 months; 52.9% male) at two time points separated by approximately 1 year in Hong Kong, China. At times 1 and 2, children's school readiness was assessed by their teachers and parents while their emotional regulation was directly tested. Teachers also rated children's emotional regulation at both time points. The results from the two reciprocal path models showed that, controlling for the corresponding autoregressive effects, school readiness at time 1 was predictive of emotional regulation at time 2. However, emotional regulation at time 1 did not emerge as a significant predictor of school readiness at time 2. Theoretically, these results underscored children's school readiness as a potential contributor to their emotional regulation. Practically, these findings suggested the utility of supporting children's school readiness to foster their emotional regulation. Copyright © 2019 John Wiley & Sons Ltd.