The researcher conducted a true experimental study to evaluate the effectiveness of the structured teaching programme on knowledge of polycystic ovarian disease among adolescent girls in the selected schools of Rohtas, Bihar, India. The study was conducted among randomly selected 60 adolescent girls from the selected schools of Rohtas, Bihar. After obtaining the research consent from the participants the researcher assessed the knowledge level of the study participants using a self-administered tool, semi structured questionnaire on polycystic ovarian disease. After which the structured teaching programme was administered to the participants followed by a post-test. After organizing and analyzing the data the researcher found that out of 60 study participants highly 63.3% of girls had average knowledge, 26.7% of girls had poor knowledge and 10% of girls had good knowledge during the pre-test knowledge score. After the planned teaching programme differently changed the girl’s knowledge, whereas the post-test knowledge score majority of 95% of girls had good knowledge, 35% of girls had average knowledge regarding the prevention and management of polycystic ovarian disease. The paired “t” value comparison was 19.49 while df 59 and the p-value for this comparison was significant (0.0001) which is less than the normal p-value (<0.02), study conclude that the planned teaching programme was proved significantly higher effective in improving the knowledge of adolescent girls regarding polycystic ovarian disease. On associating the demographic variable with the pre-test knowledge, it showed that there was no significant association. The Majority of the adolescent girls has no knowledge regarding PCOD. Deficit of knowledge regarding prevention and management of PCOD existed in varying degree of adolescent girls in all the learning area. The structured Teaching Programme utilized in this study was effective in imparting the knowledge of prevention and management of PCOD.