Back ground and objectives: Self-medication is the use of medicines by the people on their own inventiveness or on the suggestion of others without consulting a qualified health care professional; its practice is continuously increasing worldwide. The aim of this study was addressing the prevalence of self-medication in Erbil city. Methods: This cross sectional, health care center based study was conducted in five primary health care centers of Erbil city, data was collected by direct interviewing with 500 adult patients by using questionnaire. Results: The Prevalence of self-medication was 52.6%, 64.6% of the users practiced it in the past 2 weeks before the survey, significant association was found between its practice and; urban residency (p value <0.001), high socio-economic status (p value 0.004), hearing about side effect (p value 0.013), and patients who experienced side effect (p value <0.001), self-medication was for many reasons; most commonly due to previous benefit (41.7%). Medications were got from pharmacy by (70.5%); source of information about the used drug was mostly from previous prescription (44.1%). Analgesics and antibiotics were the most frequent drugs used by the respondents. Common cold was the most common condition for which drug was used without prescription followed by headache. Conclusion: Self-medication is a common practice in Erbil-city, its prevalence varied significantly with a number of socio-demographic factors and some patients' knowledge and practices about the drugs. Many patients can easily practice self-medication for the management of wide range of conditions whether simple or not. The pharmacies are the main source of getting medications.