The study investigated whether mastery motivational strategies could enhance the effectiveness of life skills interventions for HIV education through sport. A quasi field experimental study was conducted in Tanzania with at-risk children (n= 564) randomly grouped into two intervention groups and one control group. The intervention groups received AIDS education using trained peer coaches in football, with one group using mastery strategies. Children in the intervention groups all reported significantly greater HIV knowledge, and positive attitudes and safe-sex behavioural intentions. The mastery motivational strategies reliably enhanced risk reduction for some of the variables. Canonical correlation analysis revealed meaningful relationships of mastery strategies with the variables. The life skills intervention through sport for HIV risk reduction was effective, and mastery motivational strategies enhanced that effectiveness.