OBJECTIVES: ART has dramatically increased the life expectancy of HIV-infected patients and its adherence has been strongly correlated with viral suppression, reduced rates of resistance, an increase in survival, and improved quality of life. The study evaluated medication adherence, the association of medication adherence with occupation and educational status and identified possible causes of non-adherence in HIV-infected patients after 6 months on ART. METHODS: In a cross-sectional survey, medication adherence of 118 HIV-infected patients was evaluated using a self-administered study-specific 16-items questionnaire after 6 months on ART. Patients’ self-report adherence assessment method was used. Chi square statistics was used to test the association of adherence with occupation and education at 95% CI. RESULTS: The mean age of the 118 HIV-infected ART patients was 33.89 (95%CI, 29.63-38.15) years; and majority (82.2%) were between the ages of 26-45years; 60.2% were females, 80.5% attained secondary education at the least, while 77.1% employed. All participants reported being counselled on the benefits of ART and medication adherence at ART initiation. On assessment of participants’ knowledge of the benefits of ART and medication adherence, 92.2% reported correctly, 2.9% reported wrongly that ART is a cure for HIV while 4.9% did not respond. Medication adherence level reported among participants was 79.1%. Educational status was not associated with adherence (p>0.05) unlike the occupational status which was associated with adherence (p<0.05). The major reasons reported for non-adherence were busy at work or school (33.1%), forgetfulness (15.5%), fasting (12.0%), and travelled or moved away from home (10.6%). CONCLUSIONS: The medication adherence level among participants was somewhat poor compared to the desired value of >95%; occupational status was associated with adherence unlike the educational status. Consequently, busy at work or school was a major reason for non-adherence to medication. Routine evaluation of medication adherence and intervention in clinical practice is recommended.