The relationships of achievement participation motivation, goal orientations and perceived physical ability were investigated in young competitive Brazilian swimmers. Four hundred and twenty five swimmers (287 males and 138 females, ranging in age from 11 to 25 years) completed the Participation Motivation Inventory (PMI), the Task and Ego Orientation in Sport Questionnaire (TEOSQ), and the Perceived Physical Ability Scale (PPA). Findings provided evidence for the validity and reliability of the questionnaires. Regression analyses showed that ego orientation predicted motives for participation related to status and fitness. In contrast, task orientation predicted motivational variables related with competition, energy release and skills/health. Perceived physical ability predicted variables with different degrees of self-determination.