This study investigated the relationship between improvement in Total Positive Self-concept scores and increase in sports skills before and after training of 10 weeks for 45 minutes daily by 12- to 14-yr.-old junior high school and 16- to 18-yr.-old senior high school boys and girls. The 288 subjects were selected using a stratified (intact class) random technique. Subjects were randomly assigned to different sports, 96 to field-hockey and 96 to athletics (32 to discuss, 32 to long jump, and 32 to sprints). 96 control subjects were randomly selected from one class of each age bracket. Analysis of covariance showed that the trained subjects scored significantly higher in total positive self. A positive correlation between gain in sports skill and increase in self-concept scores was noted for both boys and girls within each age group. Age and sex had no effect on this pattern. The result supports inclusion of success-oriented sports in the high school curriculum.