The meta-analysis examined the effect of moral development on 4 domains of action (real life, honesty, altruism, and resistance to conformity), and on action in general. The database, comprised by 151 studies across 71 years, stemmed from a previous narrative synthesis conducted by Blasi (1980) , updated with studies published up to 2013. Results showed that (a) moral development was significantly related to action in general and to each domain, (b) the effect sizes were similar for altruism, real life, and resistance to conformity, with coefficients higher than r = .20, (c) the effect size for honesty was lower than for the other 3 types of behaviors, and (d) demographic or methodological variables did not affect the association between moral development and action. Discussion centers on similarities among domains of action, perfect and imperfect duties, and the need for other constructs to account for moral action.