Background: The World Health Organization (WHO) classifies substance abuse as one of the frequent activities that constitute "negative risk-taking," particularly among teenagers and young adults. Objective: We assessed the prevalence, correlates and effects of substance abuse among pharmacy students in a Nigerian university. Methods: This study was a questionnaire-based prospective cross-sectional study. Descriptive statistics of frequency, mean, and standard deviation was used to summarize the data, The relationship between categorical variables was determined using the Pearson Chi square (X2) test, with a P value of <0.05 considered statistically significant. Results: Overall, 150 questionnaires were distributed for the study and retrieved. 147 (98%) of the participants were aged 20-25 years, 2 (1.3%) of the participants were aged 25-30 while 1 (0.7%) was above 35years. Out of the 150 participants, 75 (50%) were males and 75 (50%) were females. Most of the participants 98 (65.3%) were in 400 level while the rest52 (34.7%). About 136 (90.7%) of participants disagreed to having family history of alcohol use while 14 (9.3%) agreed to that. Most of the participants 124 (82.7%) were actively involved in religion. The p-value for the use a substance before passively was p= 0.000 and actively p= 0.000. Conclusion: The prevalence of substance abuse among the respondents was high. The lifestyle of people in their immediate environment significantly affects the therapeutic outcome of patients directly or indirectly. Alcohol was the most abused substance. Stress relief, peer pressure, curiosity and recreation have been identified as the major reasons why the students abuse drugs. It is expected that health providers maintain high level of health standard both physically and psychologically in order to be fit enough to administer treatment to the public. For this reason, proper attention must be given to health providers in their formative years in college to reduce to the ba