Self-medication patterns in adults depend on sex. Self-medication among students is very common, but little is known about the influence of sex. The aim of the study was to determine the incidence of self-medication college students and to determine the effect of sex on self-medication patterns. A web based incidence study conducted on a sample of Slovenian university students. The main outcome measures were percentages of male and female students reporting the use of self-medication in the past year A majority of students (92.3%) reported the use of some sort of self-medication in the past year. Most female students (94.1%) and most male students (90.9%) reported the use of self-medication in the past year. The difference was not statistically significant. More female students than male ones (p<0.05) acquired the drugs for self-medication in pharmacies, used OTC drugs, herbal teas, herbs, vitamins and minerals, remedies for muscle mass gain, antibiotics, benzodiazepines, antacids, acetylsalicylic acid, topical corticosteroids, and nasal decongestives only with the advice of physicians or pharmacists, and thought that increasing drug dosage can be dangerous, that in case of side effects physicians' help must be sought, that no drug can be used during pregnancy, and that self-treatment can mask the symptoms and signs of diseases so the physicians can overlook them easily. Sex appears to be important factor in self-medication patterns even in young adults, such as students. The physicians should actively seek the presence of self-medication in this population. Inappropriate or unsafe use should be properly addressed and managed.