Objectives: The aim of this study was to summarize the available evidence on the extent of the association between moral disengagement (MD) and prosocial behavior (PB) and antisocial behavior (AB) in sport., Design: A systematic review and meta-analysis., Methods: Seven databases were systematically searched and literature screening. The CMA Version 3.3 was applied to estimate confidence intervals for the average effect sizes. The Q statistic and I-squared index were used to test for heterogeneity. Funnel plots, fail-safe numbers (N fs ), and Egger's linear regression were used to analyze publication bias. Sensitivity analyses were used to identify outliers, and subgroup analyses and meta-regression were used to test potential moderators., Results: Twenty-nine studies were included, and the results showed the negative correlation between MD and PB in sport was small in size (r = -0.22, 95 % CI [-0.30, -0.14]), while the positive correlation between MD and AB in sport was large in size (r = 0.53, 95 % CI [0.48, 0.59]). More specifically, MD was negatively correlated with PB toward teammates (r = -0.07, 95 % CI [-0.12, -0.01]) and PB toward opponents (r = -0.09, 95 % CI [-0.18, -0.01]), with very small effect sizes, but positively correlated with AB toward teammates (r = 0.43, 95 % CI [0.35, 0.51]) and AB toward opponents (r = 0.56, 95 % CI [0.49, 0.63]), with medium to large effect sizes. Subgroup analyses revealed that individualism-collectivism and sports type moderated the association between MD and AB., Discussion: Mechanisms of moral disengagement were more strongly associated with antisocial behaviors than prosocial behaviors in sport. In the future, there is a necessity to conduct further research on non-contact sports and different subtypes of antisocial behavior using high-quality study designs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)