To enhance psychological adjustment, Vipassana meditation assists individuals to perceive the transitory nature of the self. Because the consequences of this potentially troubling insight are not well understood, changes in self-concept and ego defense mechanisms of two cohorts (N₁ = 222, N₂ = 216) of young (M = 18.03 years) Thai participants who attended separate seven-day Vipassana meditation retreats and a nontreated control group (N = 281) were compared. Multivariate statistical analysis revealed positive gains in all areas of self-representation among meditators relative to controls (p < .00 1). Ego defense mechanisms of the meditation participants also underwent significant change (p <.0001) with coping becoming characterized by greater maturity and tolerance of common stressors. Increases in Buddhist beliefs were significantly correlated with heightened self-esteem and less impulsiveness (p < .00 1). Theoretical and applied implications of the findings are discussed