Background: Iron deficiency is the leading single nutrient deficiency in the world affecting the lives of more than 2 billion people, particularly in developing countries. Iron-foliate supplementation (IFAS) program is a globally recommended intervention to overcome this problem. Despite this program, in Ethiopia, <1% took an iron supplement for the recommended period (90 days or more) during their last pregnancy. The adherence to iron folate is not known in the study area and this study may answer the current situation on adherence to IFA supplementation and associated factors to iron folate supplementation. Objective: To assess adherence to iron - folate supplementation and associated factors among pregnant women attending Antenatal care clinic in public health facilities of Tembaro district, southern Ethiopia, 2017. Methods and Materials: A Health facility based cross sectional study was conducted using quantitative methods on 405 pregnant women attending Antenatal care clinic in four public health facilities from January 15, to February 14/2018. Systematic random sampling method was used to select study participants. An interview with pre tested structured questionnaire was conducted. Data was entered into Epi info version 7 and exported to Statistical Package for Social Science (SPSS) version 20.0 for analysis. Univariate, bivariate and multivariable logistic regression with odds ratios (OR) along with the 95% confidence interval was computed and interpreted. A P-value <0.05 was declared as statistically significant. Result: - The adherence rate to iron folic acid supplement was 55.9%. History of anemia in current pregnancy(AOR=3.03,95%CI=1.19-7.70); knowledge on cause of anemia (AOR=4.93,95%CI=1.45-16.70);knowledge status about anemia (AOR=5.56,95%CI=1.6618.54); knowledge status about IFAS (AOR=3.98,95%CI=1.90-8.33), and number of months pregnant women supplied with IFA in current pregnancy(AOR=1.85,95%CI=1.02-3.35) were significantly associated factors with Adherence to iron folic acid supplement. Forgetfulness, supply shortage and perceived (experienced) side effects of IFA therapy were the important factors for non-adherence. Conclusion and Recommendation:-Adherence rate to iron folate acid supplement was low. Increasing awareness on IFAS, ensuring the supply timely is recommended at each level.