Abstract: Adolescence is a stage of struggle for identity. It is evidenced by rebelliousness, adventure seeking behavior and oppositional defense. The future citizens are at great risk for early initiation to drugs and other psycho active substances. Therefore, a quasi experimental study to assess the effectiveness of structured teaching programme was used to assess knowledge of adolescents regarding substance use. One group pre-test post-test design was used for this study. Convenient sampling technique is used on the sample for the present study consists of 91 adolescents age of 17- 18 yrs. from selected B.Sc. Nursing colleges at Udaipur district of Rajasthan. Self administered Knowledge questionnaires (Pre test – Post test) were administered. The collected data were analyzed by using descriptive & inferential statistics based on predefined objectives of the study. Present study shows that pre test knowledge level of students was significantly (P<0.05) less towards substance abuse. Study reveals that proper education (STP) enhance post test knowledge among students regarding substance abuse.