Abstract Introduction: HIV attacks an immune cell called the CD4 cell which is responsible for the body’s immune response to infectious agents. An infected person’s CD4cell count can be used to monitor the progression of the disease. The objective of the study was to identify factors that affect bivariate longitudinal change of CD4 count and weight with time to death of HIV patients. Methods: Retrospective study design was used from Felege Hiwot specialized and Referral Hospital. The data was collected from patient’s chart from January 2013 to December 2017. The Kaplan-Meier survival estimate and Log-Rank test were used to compare the survival time. Joint model of bivariate longitudinal and time to event model was used to identify factors of longitudinal change of CD4 count and weight with time to death jointly. For the longitudinal part linear mixed effect model and for the survival part Cox PH model were used. Result: Patients with greater than ten hemoglobin level were 3.32 times less likely to die than patients with less than or equal to ten hemoglobin level. Male patients had 3.28 times higher risk of mortality than female patients. As the baseline age of patients increase by one year the average log of CD4 count also decrease by 0.2329. The average log of CD4 count for patients whose clinical stage was stage II, stage III and stage IV was decreased as compared to patients whose clinical stage was stage I by 0.373, 0.61 and 1.11 respectively. As the number of visit increased the average log CD4 count of patients who were fair and good adhered was higher than the average log CD4 count of patients who were poor adhered by 0.0642 and 0.1097 respectively. As age increased in one year the mean log weight of patients increased by 0.1355. As the number of visit increased by one unit, the log weight of patients whose functional status was bedridden was less than the log weight of patients whose functional status was ambulatory by 0.0728 kg. When the number of visit increased by one unit, the patients whose functional status was able to work had higher mean log weight as compared with the patients whose functional status was ambulatory at the initiation of treatment by 0.0453. Conclusion: From our finding we conclude that gender and hemoglobin were risk factors of mortality of HIV patients. Age, WHO clinical stage, baseline CD4 and interaction of adherence by visit were factors of CD4 count. Age, baseline weight and interaction of functional status by visit were significant predictors of weight. Key words: HIV, CD4 count, Weight, linear mixed effect model, survival model, joint model