The purpose of the study was to find out the effect of yoga practice on personality and self-confidence among various level school adolescent boys. For this purpose, 90 adolescent boys studying in various level schools in and around Theni, Tamilnadu, India were selected as subjects, with the age group of 12 to 15 years. Further, they were divided into two groups (n=45), namely group – I which underwent yoga practice six days (Monday to Saturday) per week for twelve weeks and group – II acted as control, which did not participate any type of special training apart from their regular day to day activities. Prior to and after the experimental period, the subjects were tested on personality and self-confidence. Personality was assessed by using Congil Personality Scale and the Agnihotri Self - confidence scale was used to measure the self-confidence before and after the experimentation. The Analysis of Covariance (ANCOVA) was used to find out any significant difference between the yoga practice group and control group. The result of the study shows that the yogic practice group had significant (P < 0.05) effect on the personality and self-confidence.