Abstract: The CD4 count is a critical measure of immune system and is used as an important biomarker for describing the progress to AIDS in children and adults. Usually infants will be having better CD4 count with good immune system as age progresses the CD4 count start declining. .Present study aims to describe the trend of CD4 count with respect to different age group of children. A prospective and retrospective cohort data was collected from Government ART centers of Bangalore city.