Background: Self-medication is a public health concern because of drug misuse/abuse and its medical, social and psychological problems.Aim: Given the growing prevalence of self-medication, the present study aims to determine the prevalence and causes of self-medication among students of Kerman University of Medical Sciences. Method:This cross-sectional study was conducted in 2014 on 550 students who were selected through multistage sampling from Kerman University of Medical Sciences, Kerman, in southeast Iran. Data was collected through a self-report questionnaire. Test-retest reliability and content validity of this questionnaire were confirmed. Data analysis was carried out using descriptive and inferential statistics via t-test and analysis of variance (ANOVA). Results:The prevalence of self-medication among students was 50.2%. The most common cause of self-medication was related to students' knowledge about the diseases and medications (58.7%). The majority of drugs consumed arbitrarily included cough and cold medications (94.5%); analgesics (89.9%); antihistamines (80.0%); herbal drugs and distillates (78.9%); vitamins, minerals, dietary supplements and energizers (71.5%); antibiotics (61.8%); and gastrointestinal drugs (54.9%), respectively. The most common illness that led to self-medication was the common cold (95.4%), and the most important source of information regarding self-medication was the students' own scientific knowledge of medical drugs (80.6%). Conclusion:Due to the adverse effects of self-medication, drug dependency, and microbial resistance and the relatively high prevalence of self-medication among students in this study, it would be advisable to organize awareness campaigns to further educate students about self-medication.