Background: Adherence to Anti-Retroviral Therapy (ART) is critical for optimalrnvirologic suppression and improved CD4+ cell count that in turn determines the survivalrnof People Living with HIV/AIDS (PLWHA) on ART. So far a range of predictors ofrnadherence to ART in many different social and cultural settings have been identified.rnHowever, household food and nutrition security as predictor of adherence to ART is lessrnunderstood.rnObjective: The main objective of this research project is to assess the effect of householdrnfood and nutrition security on adherence to ART and treatment outcomes.rnMethod: A cross-sectional study was conducted to assess the effect of household foodrnand nutrition security on adherence to ART and treatment outcomes. Both quantitativernand qualitative research methods were applied to triangulate the findings of one withrnanother. Adult PLWHA on ART for at least 3 months were the study participants.rnAvailability of enough food/money to buy one, behavioral and subjective questions, mealrnfrequency, dietary diversity, food aid and BMI were used as indicators to measure thernhousehold food and nutrition security situation of PLWHA and self-reported adherencernas an indicator to measure adherence to ART. Change in CD4+ cell count, body weight,rnfunctional status and frequency of opportunistic infections were used to measurerntreatment outcomes.rnResult: Based on food security assessment core module close to 90% of PLWHA onrnART in Dire Dawa were food insecure and 30.1% had at least mild malnutrition. Onrnpatient self report of adherence 96.6% of them were adherent to 95% of the ART drugsrnprescribed. The median change in CD4 count after 6 months and the median change inrnweight after 3 months of ART were 116 (IQR 82-182) and 3kg (IQR 1-6kg) respectively.rnReported diarrhea and lung disease among the study participants were 17.9% and 54.1%rnrespectively. Food and nutrition security indicators were associated with treatmentrnImpact of food and nutrition security on adherence to ART and treatment outcomesrnAAU, FM, DCH, RH specialty track IXrnoutcomes. Food aid contributed to functional improvement (OR 1.89, 95% CI 1.20-2.97).rnDietary diversity and meal frequency were significantly positively correlated with changernin weight and change in CD4 count respectively (p