ABSTRACTDiabetes mellitus is a major non-communicable disease that requires continuous medications to control and prevent micro vascular and macro vascular complication of the disease. Family support, a naturally occurring resource in sub-Saharan Africa has been reported to affect medication adherence behaviour in patients with chronic health conditions. This study determined its relationship among patients living with diabetes mellitus in the index population. This was a hospital based cross-sectional study among recruited 120 adult type 2 diabetes mellitus patients aged 18-years and above attending General Outpatient Clinic of Federal Medical Centre Gusau. Out of the recruited participants only 118 of them completed the study. This study participants were recruited using systematic random sampling method over a period of 12-weeks.The Family support of the respondents was assessed using perceived family support social scale. The Morisky medication adherence scale -8 was used to measure the medication adherence of the respondents. The glycaeted haemoglobin of the respondents was measured using Clovac A1C analyser. The completed data from 118 respondents was analysed using IBM SPSS version 23. The sociodemographic and clinical characteristics of the respondents was summarized using mean with standard deviation and frequencies with percentages. The Chi square was used to determine the relationship between family support and medication adherence among the respondents. The level of significance was set at p < 0.05. Multivariate logistic regression was used to determine the independents predictors of medication adherence. The mean age of the study respondents was 51.68±8.8. About 50.8% of the respondents had good family support, 41% of them had good medication adherence and 57% of them had good glycaemic control. The relationship between family support and medication adherence among the respondents was statistically significant p = 0.036.This study found significant associations between family support and medication adherence among adults with type 2 diabetes mellitus attending a primary care clinic. Routine assessment of family support may help improve diabetes outcomes in similar settings.