Introduction: Iron deficiency is the leading single nutrient deficiency in the world affecting the lives of more than 2 billion people, accounting to over 30% of the world’s population particularly in developing countries. Pregnant women are particularly at high risk of iron deficiency due to increased nutrient requirement during pregnancy. Nationally only 0.4% of the pregnant women take Iron supplements more than 90 days of the recommended 180 days. In Amhara region 80.6% of pregnant women do not take any iron tablets or syrup during pregnancy, while 17.1% take for less than 60 days, 0.3% takes for 60-89 days and only 0.4% take for 90 days or more. The factors for this low adherence are not clearly known. Objective: To assess the level of adherence and identify factors associated with IFA supplementation among pregnant women attending antenatal clinics of selected health facilities in Borena South Wollo, Amhara region, Ethiopia, 2017. Methodology: Institution based cross sectional study was conducted and 340 pregnant women participated in Borena South Wollo, Amhara region, Ethiopia, 2017. All public health centers included in the study and Systematic random sampling method was used to select the participant and using proportional to population size allocation in all health centers. Data was entered Epi info version-7 and exported to SPSS version-20 for analysis. The association between outcome and independent variables was tested using multivariable logistic regression analysis. The strength of statistical association was measured by adjusted odds ratios and 95% confidence intervals. Result: The level of self-reported adherence to iron folate supplement use among pregnant women attending antenatal care clinics of Borena Woreda was 45.6%. Factors significantly associated with adherence to Iron and folic acid supplementation were husbands primary in education [AOR=1.95 CI 1.07-3.57], history of abortion [AOR=0.162 CI 0.050-0.53], diseases diagnosed other than anemia [AOR=0.476 CI 0.284-0.798], taking of IFA in months[AOR=2.81 CI 1.365-5.786] and encouragement to take IFA[AOR=0.125 CI 0.037-0.418]. Forgetfulness, frustration of having to take many tablets, and side effects major reasons for skipping IFA supplement. Conclusion and recommendation: Adherence to IFA supplement utilization was low in the study area. Thus, improve educational status of community and Sensitization of pregnant women by health providers to supplements and increasing use of iron and folate throughout pregnancy.