Introduction: self-medication can cause significant challenges for the individuals and community, especially in women during pregnancy. This study was aimed to compare the prevalence of self-medication before and during pregnancy among women in Iran.

Methods: in this cross-sectional study, a total of 384 pregnant women were evaluated for the prevalence of self-medication and its associated factors before and during pregnancy. Stratified random sampling was used as the sampling method. Descriptive statistics and chi-square and logistic regression tests were used for statistical analysis of data.

Results: the results showed that the prevalence of self-medication, in women who had become ill at least once, was 63.9% before pregnancy and 43.5% and during pregnancy. Variables such as lack of insurance, high school education and not having a child increased odds ratio of self-medication before pregnancy, while the variables of lack of insurance, not having a child or fewer number of children and no history of abortion increased the odds ratio of self-medication during pregnancy.

Conclusion: although the prevalence of self-medication during pregnancy was less than that before pregnancy, but this prevalence during pregnancy was still significant. Therefore, it seems necessary to provide public trainings for all women of reproductive age and train them about the dangers and side effects of self-medication.