The purpose of this study was to determine the relationship between implicit theories of ability and competence perceptions to changes in approach-avoidance goal adoption in two specific activities in the curriculum. Four hundred and thirty pupils, aged 11-15 years, completed measures of approach-avoidance goals, perceived competence and implicit theories of ability at the start and end of a tennis or cricket unit of work in physical education (PE). In both tennis and cricket, most of the variance in the variables under investigation was due to differences between pupils and not to differences between classes. Controlling for prior approach-avoidance goal adoption, incremental beliefs predicted change in mastery-approach goal adoption and perceptions of competence predicted change in performance-approach goal adoption over the unit of work in both tennis and cricket. Differences in the predictive pattern of antecedents to changes in goal adoption emerged between activities. (Contains 5 tables.)