Introduction: Self-medication is one of social-health problems and addressing to this matter in sensitive populations such as pregnant women because of their role as role model for other family members is very important. This study aimed to assess the knowledge, attitude and behavior of pregnant women towards self-medication, and measures should be done to increase knowledge, improve attitude and practice of pregnant women in subsequent step if necessary.

Materials & methods: A descriptive-analytical study was carried out on 300 pregnant women referring health centers of Ilam in 2.10.2013 up to10.6.2014  via sampling in two steps. Data was collected based on a researcher made questionnaire in four parts. Validity of the scale was confirmed by content validity and its reliability was also confirmed by Cronbach's coefficient (α= 0.85). The Data was analyzed by SPSS16 software.

Findings: The results showed that 71 % of the pregnant women had a medium knowledge, 75.7 % have medium attitude and 70 % have weak practice. Chi-square test showed a significant relationship between pregnant women knowledge about self-medication and their education level (p<0.05).

Discussion & Conclusions: in this study, women with lower educational level had lower knowledge towards self-medication. Considering the importance of drug use during pregnancy and its adverse effects on the fetus, it is necessary to educate women about side effects of self-medication in pregnancy. Obviously, promoting pregnant women's knowledge is necessary to change the attitude and practice towards self-medication.