<sec> <b>Objectives</b> <p>This study aimed to determine the relationship between assertion and aggression with addiction potential among students in Shahroud University of Medical Sciences.</p></sec> <sec> <b>Methods</b> <p>In this cross-sectional study conducted in 2019, 500 students of Shahroud University of Medical Sciences, were selected by multistage random sampling, for a study using the Addiction Potential Scale, and Assertion and Aggression Questionnaires. Data were analyzed using ANOVA, Chi-square, <italic>t</italic> test, Pearson’s correlation coefficient, and the linear regression model.</p></sec> <sec> <b>Results</b> <p>The mean scores of addiction potential, aggression, and assertion were 32.7 ± 17.2, 41.5 ± 12.9 and 139.4 ± 22.3, respectively. In this study, 38.8% (<italic>N</italic> = 194) of students had high aggression and 76.8% (<italic>N</italic> = 384) had high assertion. In the regression model, aggression, history of drug and addictive substances abuse, history of tobacco use, and history of alcohol abuse were significantly related to addiction potential (<italic>p</italic> ≤ 0.05). There was a negative relationship between assertion and addiction potential so that with one-unit increase in the assertion score, the addiction potential score decreased by −0.11.</p></sec> <sec> <b>Conclusion</b> <p>Given the direct relationship between aggression and addiction potential, and since more than three-quarters of the students had moderate to high aggression, it is necessary to pay more attention to this issue. Interventions may play an important role in improving the current situation.</p></sec>