The development and manifestation of gratitude in youth is unclear. We examined the effects of a grateful outlook on subjective well-being and other outcomes of positive psychological functioning in 221 early adolescents. Eleven classes were randomly assigned to either a gratitude, hassles, or control condition. Results indicated that counting blessings was associated with enhanced self-reported gratitude, optimism, life satisfaction, and decreased negative affect. Feeling grateful in response to aid mediated the relationship between experimental condition and general gratitude at the 3-week follow-up. The most significant finding was the robust relationship between gratitude and satisfaction with school experience at both the immediate post-test and 3-week follow-up. Counting blessings seems to be an effective intervention for well-being enhancement in early adolescents.