One of the biggest proposed additions for DSM-5 is a disorder characterized by the acquisition of and failure to get rid of possessions that clutter the home, creating significant problems. Although final decision abort inclusion is yet to be made, “hoarding disorder “is likely to survive as one of the newest mental conditions. A title was to assess effectiveness of structured teaching programme on knowledge regarding compulsive hoarding disorder among undergraduate students from selected colleges at Navi Mumbai.Objectives of the study: 1.To assess level of knowledge on compulsive hoarding disorder among undergraduate students of selected colleges at Navi Mumbai. 2. To assess effectiveness of structured teaching programme on knowledge regarding compulsive hoarding disorder by comparing the pretest and posttest knowledge score among undergraduate students. 3. To find out association between pre interventional knowledge score with selected socio demographic variables.Material &Method:A pre experimental one group pre-test and post-test design was adopted to assess the effectiveness of structured teaching program on compulsive hording disorder. Sample size of 100 undergraduate students were collected from selected colleges using non probability convenient sampling technique. Data collection tool: Questionnaire was developed by the investigator after review of literature on similar topics and after consulting the experts. Questionnaire was developed to observe or measure the variables under study. Description of the tool: A self-administered structured questionnaire was prepared to determine the knowledge regarding compulsive hording disorder which consisted two sections: A self-administered structured knowledge questionnaire was validated by the experts. Reliability of the tool was checked. Reliability score was 0.761 which suggests tool was reliable. Results and conclusion: Major findings show that in pretest the mean knowledge score was 6.69 whereas in posttest the mean score was 12.96 with mean 6.27 with knowledge gain of 31.35%. Findings related to level of knowledge regarding compulsive hoarding disorder reveals that in pretest majority 62% were having average knowledge level, 31% were having poor knowledge and only 7% were having good knowledge level but none of the participants were having excellent knowledge level. Whereas in posttest, 74% were having good knowledge level, 15% were having average knowledge level and 11% were having excellent knowledge and none of the sample had poor knowledge. Findings related to effectiveness of structured teaching program shows that there is significant difference between mean pre-test and post-test knowledge score (t=47.889, p<0.05). This indicates structured teaching programme is effective in increasing undergraduate students’ knowledge regarding compulsive hoarding disorder. Finding related to association between knowledge and selected demographic variables shows that the calculated p value for all the variables such as age, gender, educational qualification, previous knowledge. Conclusion: The finding of study reveals that structured teaching programme is effective in improving the knowledge of undergraduate students regarding compulsive hording disorder.