Introduction: Folic acid is one of the most important vitamins for women of reproductive ages, especially before conception and during pregnancy. Many researches have shown the role of folic acid in prevention of fetal malformations especially neural tube defects, anemia, cardiovascular disease and some cancers.

Material and Methods: This research is a semi-experimental study. A sample of 130 married women at reproductive ages (15-45 year) referring to health centers in Kermanshah was selected randomly. The tool for collecting data was questionnaire. After filling the pretest questionnaire, each woman participated in a face to face 15 minutes educational session. Two weeks later the same questionnaire was filled by the participant. To analyze the data, the descriptive statistics, frequency distribution charts, the mean and central tendency as well as validating statistics (2 test and t test) was used.

Results: The results indicated that there was a statistically significant difference in amount of knowledge (p 0.0001, t=-27.381) and the amount of usage (p=0.0001, 2 = 42.968) of folic acid supplement before and after education. This difference was more prominent in women between 25-29 years of age, self-employed, with diploma degree, housewives, having diploma holding husbands and first time pregnancies.

Conclusion: The amount of information and usage of folic acid supplement increased significantly after education. This finding reveals the importance of health education and the important role of health personnel such as midwives. Therefore, it is suggested that women of reproductive ages be informed of importance of taking folic acid supplement.