This study investigated Assertiveness Training and Psycho-education as preventive measures of drug abuse among secondary school students in Makurdi Local Government Area. The study adopted a pre-test, post-test and control group experimental design with a 3x2 factorial matrix. The sampling techniques adopted were the simple random method where each student was given an opportunity to be selected, and randomization of experimental groups and the control group to the schools through balloting was also done. Drug abuse prevention questionnaire (DAPQ), a standardized instrument developed by Skinner (1982), with a reliability coefficient of .97 were used for data collection. A total of 40 secondary school students made up of 28 males and 12 females with ages ranging from 15-23 years took part in the study. They also had a mean age of 18.38 Three hypotheses were raised and tested. The results obtained revealed that firstly, assertiveness training and psycho-education have significant treatment effects in the prevention of drug abuse among secondary school students (F(2)= 6.88; P< 0.05 ). Secondly, sex had no significant effect on prevention of drug abuse F(1)= 0.32; P> 0.05 and thirdly, there was also no statistically significant interaction effects on drug abuse among secondary school students F(2)= 0.82; P> 0.05. Therefore, it is recommended that high premium is placed on developing and mainstreaming prevention programs on drug abuse into the school curriculum in secondary schools for students to become more assertive and acquire more knowledge on drugs and its effects on mental health.