Background and Aim: Nowadays, scientific and industrial advances in medical field and pharmaceutics have provided access to various types of medications which, without proper monitoring, can lead to willful drug use. The present study aimed at determining self-medication epidemiology and its related factors in pharmacy visitors in Birjand in 2015.

Materials and Methods: This analytical descriptive study was conducted on 944 Birjand pharmacy visitors, using stratified randomized sampling in the winter and spring of 2015. The necessary data was obtained by means of a validated and reliable questionnaire. Then, it was fed into SPSS (V:19) software and was analysed using the statistical testes X² ,independent T, Mann Whitney, Kruskal-Wallis ,and Tukey at the significant level P<0.05.

Results: Mean age of the participants was 32.8 ± 10.8 years. Among them, 84.5% from whom 58% were men, expressed their inappropriate self-medication. Common cold, allergy (61.4%) and analgesics (43.9%) had the highest rate of use. Unavailability of physicians (33%), easy access to medications in pharmacies (44.5%) and similar prescriptions (30.6%) were the main reasons for inappropriate self- medication.

Conclusion: It was found that the inappropriate use of drugs, mainly in common cold, analgesic and antibiotic drugs, was high in the study population. The easy access to medicines pharmacies is probably the most important factor of the self medication.