© 2015, Copyright © Taylor & Francis Group, LLC. Engagement in leisure activities during retirement and its relationship to retirement adjustment were investigated. Psychosocial mediators included mastery, self-efficacy for retirement (SE-R) and activities (SE-A), positive (PA) and negative affect (NA). Resources investigated included physical health and finances. Leisure activities examined were social, home entertainment, chores, light exercise, vigorous exercise, and education. Data were gathered from a sample consisting of 243 retirees. Direct predictors of retirement adjustment included finances, health, mastery, SE-R and SE-A. Social activities were the best predictor of a wide range of positive outcomes, including PA, mastery, SE-R and SE-A. Educational activities improved SE-R. Being involved in a broader range of activities was associated with PA, mastery and SE-A. Familiarity and enjoyment of activities were implicated in the maintenance and continuation of activities at post-retirement. Research findings have implications for aged-care and other retirement service providers, as well as for individuals.