Background: In HIV infected individuals immunologic and hematologic abnormalities are common and they increase the risk of morbidity and mortality. However little is known about the profile of immunologic and hematologic abnormalities in Ethiopia in those children who are on Highly Active Antiretroviral Therapy. Evaluating the haematological and immunological parameters in HIV/ AIDS patients on HAART is important in order to monitor the body responses to the drugs. Therefore, assessment of haematological and immunological changes in HIV/ AIDS patients in HAART is of a paramount importance.rnObjective: the main objective of this study was to assess immunologic and hematologic profile of HIV infected children on highly active antiretroviral therapy in Zewditu Memorial Hospital.rnMethodology: A retrospective cohort study was conducted among HIV infected children who received HAART between September 2008 and March 2013 at ART clinic of Zewditu Memorial Hospital in Addis Ababa, Ethiopia. Data were collected using structured questionnaire that included variables related to socio-demographic characteristics, immunohematological profiles and clinical conditions of the study individuals. Data was analyzed using SPSS for Windows version 16.0 soft ware.rnResult: The mean level of hemoglobin, thrombocyte count and CD4 count showed statistically significant increment from the baseline (p-value