Highly active antiretroviral therapy (HAART) has significantly reduced mortality caused byrnhuman immuno-deficiency virus (HIV) by enhancing the physiological and immunologicalrnability to counterattack against the virus and increases the life expectancy. Once started, thernantiretroviral treatment should be continued lifelong and adherence to this treatment should bernnearly perfect to enable long-term efficacy. A continuous and life-long treatment withrnHAART may lead to a broad spectrum of significant toxicities. As a result many patientsrninterrupt their HAART without the knowledge and advice of the clinicians and this cause thernpatient immune to degrade and even cause to death. Therefore, this study is an attempt tornexamine the predictive factors of interruption duration in patients who interrupt their ARVrndrugs treatment.rnThe study is a retrospective cohort study of HIV/AIDS patients under HAART butrndiscontinued their treatment for at least one month, which comprises a total of 723 patientsrnfrom Zewditu Memorial Hospital. Of these patients about 67% resumed their treatment. In thernanalysis of data the Kaplan-Meier survival estimator and Cox proportional hazards regressionrnmodel are used. Based on the data analysis, it is found that main effects: education, baselinernage, baseline weight, CD4 count at the start of HAART and prior to interruption, duration onrnHAART and interaction effects: marital status with disease duration and marital status withrnsex are important factors that are related to time to resumption of HAART.rnIn general, HIV/AIDS patients who have prolonged treatment interruption are characterizedrnby having lower level of education, younger age, high weight, higher CD4 count at the start ofrnHAART, lower CD4 count prior to treatment interruption, longer duration on treatmentrnfollow-up and currently not married and male patients with longer disease duration