Background: Iron deficiency anemia is affecting the lives of 2 billion people which accounts almost 30% of world`s population. It is a major nutrient deficiency; contributor of morbidity and mortality of pregnant women globally. Even though, such a problem could be prevented by an adequate prenatal care like iron/ folic acid supplementation as WHO recommended; adherence to the provided supplementation is still a challenge. Objective: To assessadherence status of iron/ folic acid supplement and associated factorsamong antenatal care attendant pregnant women in Fogera District, North-West Ethiopia. Methods: Community based cross-sectionalstudy was conducted on a sample of 413 pregnant women in Fogera district from July 2 - 28, 2018. Systematic random sampling method was used to select study subjects. Pregnant mothers were interviewed and the collected data using a pretested structured Amharic questionnaire were edited, coded and entered to Epi Info 7 and exported to SPSS version 23.00 packages. Bivarate and multivariable analysis was computed to identify factors associated with adherence to iron/ folic acid supplementation. Results: Four hundered three pregnant women who started to take iron/ folic acid supplement were enerolled.In this study 37.47% of respondents were adherence to iron/ folic acid supplementation. In multivariable analysis; age, educational status of pregnant women, frequency of ANC visit, knowledge about anemia, knowledge about iron/ folic acid supplement were significantly associated with iron/ folic acid supplement adherence. Undesirable effect like unpleasant taste of iron/ folic acid supplementation was the reason given for non adherence. Conclusion: Adherence status of iron/ folic acid supplementation is low in the study area. Increasing female education and increasing knowledge about anemia, knowledge about iron/ folic acid supplementation and promotion of antenatal care are recommended to increase adherence to iron/ folic acid supplementation.