Background: Psychiatric patents have a predisposition towards developing venous thromboembolism (VTE). This risk is largely related to the medications used in treating the disorders. The objective of the study was to assess the risk of venous thromboembolism in Psychiatric Patients on antipsychotic drugs using platelet indices. Methodology: This was a case-control study involving 92 participants comprising of 51-psychiatric patients on antipsychotics and 41 non psychiatric persons (blood donors) as controls. Blood (2.5 mls) was collected from both subjects and controls into separate EDTA anticoagulant tubes. A full blood count was performed on each sample using Haematology Auto analyser. Platelet count, mean platelet volume (MPV) and platelet distribution width (PDW) were extracted from the result of each participant. Clinical data of each subjects including age, sex, weight, height, duration