The purpose of the study was to find out the influence of yoga intervention on assertiveness among under graduate students. For this purpose, 20 college going girls were randomly selected from Private Institution, Chennai. Their age was ranged between 19 and 21 years. The study was conducted after college hours so that the class routine was not disturbed. Further, the selected twenty subjects were randomly assigned into experimental group (Group I (n=10)) and control group (Group II (n = 10)). The experimental group underwent 8 weeks of practices which include Prayer, loosening exercises, Asana, pranayama and OM chanting for six days (i.e. Monday to Saturday) in a week. Each yoga session consisted of 5 minutes of loosening exercises, 5 minutes of Surya Namaskar, 20 minutes of asana, 10 minutes of pranayama and 5 minutes of OM meditation. Control group didn’t undergo any such practices. Finally, when the training period of eight weeks was over, all the subjects of experimental and control groups were assessed for assertiveness. Standardized assertiveness questionnaire Rathus assertiveness Schedule (30 items) were used for Pre-test and post-test of both control group and experimental group before and after the training period. The eight weeks yogic practices significantly increase the assertiveness among under graduate students.