Background: Thrombocytopenia plays an important role in the diagnosis of malaria in most countries because of the rapid decrease of platelets during malaria onset and also in severe forms of the disease. The study sought to assess platelet numbers and determine the prevalence of malarial thrombocytopenia among children with febrile malaria at the Korle-Bu Teaching Hospital (KBTH). Methodology: It was a cross-sectional study carried out in the Department of Child Health and the Polyclinic of KBTH from April to July 2018. A total of 100 children aged from 1 to 12 years who tested malaria positive for both thick and thin blood film and Rapid Diagnostic Tests (RDTs) were recruited into the study. Venous blood sample was obtained from the children and analyzed for platelet count using a haematology auto analyzer. Parasite speciation and quantification was used to classify the disease into mild, moderate and severe, and platelet numbers were also categorized into low, normal and high. Data obtained was then analyzed for prevalence of malarial thrombocytopenia in severe malaria. Results: The total studied participants were 100, 61 (61%) were males whiles 39 (39%) were females. Both severe malaria and thrombocytopenia were mostly seen in children less than 5 years of age and the males recorded more thrombocytopenia (66%) and normal platelet numbers 34 (64.2%) than the females. There was a significant higher percentage of malaria children with thrombocytosis being females (64%) as compared to those being males (36%). 53 (53%) children had normal platelet numbers, 33 (33%) had thrombocytopenia, and 14 (14%) had thrombocytosis. The prevalence of uncomplicated malaria and complicated malaria were 80% and 20% respectively. The overall prevalence of thrombocytopenia was 33%, and the prevalence of thrombocytopenia in uncomplicated and severe malaria was 18.8% and 90% respectively. The prevalence of malaria types among children with thrombocytopenia was assessed. Out of the 33 (33%) patients who had thrombocytopenia, 15 (45.5%) of them had uncomplicated malaria and 18 (54.5%) of them had complicated or severe malaria. No child was found to have thrombocytosis during complicated malaria. Conclusion: The study indicates a significant higher prevalence of thrombocytopenia in severe malaria among children at the Korle-Bu Teaching Hospital, and this could be used as a useful indicator to investigate malaria or as a diagnostic clue for malaria in children.