Introduction: Self-medication is a common behavior in society and a frequent practice among university students. It is a severe health problem that affects the familiar, individual, and collective health.

Objective: To determine the reasons that lead to self-medication in nursing students at the Santiago de Cali University, Colombia.

Method: A descriptive cross-sectional study was conducted with 234 undergraduate nursing students. The study was carried out between April and May 2020. To calculate the sample, we applied the statistical formula with a confidence level of 95%, a margin of error of 5%, and a desired confidence interval of 5%. We used a virtual, validated questionnaire, which the students filled out voluntarily. Results: Ninety percent of the participating students were between 18–26 years old. The mean was 21.7, while the median was 20, and the mode was 19 years. A total of 81% were women. A total of 69% of the students stated that they self-medicate. Pain relievers are the drugs of choice for self-medication. Among the reasons for self-medication, it was found that: 44% of participants do not believe that it is necessary to consult a doctor, while 20% expressed not having the time to consult with a doctor. The participants obtain the medication in the pharmacy (95%). Conclusions: Self-medication is a common practice in nursing students between the first and fifth semesters of the Santiago de Cali University. Although it is recognized as a risky practice, the prevalence is high.