Background: A frequent blood disorder detected in the newborn is reduced platelet number. The causes of thrombocytopenia, its treatment methods, and the outcome of the condition should be evaluated for better illness management. Typically, around one-third of platelets are situated within the spleen. Thrombocytopenia is defined by a platelet count below 150x10^9/L. Objective: To evaluate the frequency of causes of thrombocytopenia in neonates admitted to a tertiary care medical center. Methods: A cross-sectional investigation was conducted. Blood specimens were gathered in EDTA tube and assessed on hematology analyzer Nihon Kohen for full blood count. Peripheral smear were inspected, serum bilirubin and CRP were measured.