Introduction & Objective: In the last decade, indiscriminate self medication has increased in our country that can lead to many complications. The aim of this study was to determine the causes of self-medication among Hamadan province pharmacies visitors.

Materials & Methods: This cross-sectional study was conducted among 428 Hamadanprovince pharmacies visitors in the spring and summer of 2012. Sampling was conducted by classification with proportional assignment between pharmacies in different cities in Hamadan province .The data collected by questionnaires were described using SPSS-16.

Results: Pain medications (29.9%), antibiotics (20.6%) and anti-cough and cold medications (12.6%) had the highest rate of consumption. Previous use of medication, symptoms improvement (32.2%) and similar prescription (25.3%) were the main reasons of self-medication among the participants.

Conclusion: Considering the high prevalence of self medication, designing and implementing educational programs is essential to enhance perceived risks of self-medication between different groups of society.