Background: Platelets are the smallest cells in the blood and are involved in the wound healing process. Platelet transfusion is an important part of treating illnesses such as thrombocytopenia and to prevent and stop major bleedings. Platelets for transfusion are received after processing of whole blood through automated or semi-automated systems and pooling of interim platelet units received after the processing. A limit is set for the minimum total estimated platelet yield in a pool to ensure that the final product consists of enough platelets. Aim: The aim of this study was to evaluate the platelet yield index received from Reveos automatic blood processing system by comparing it to the fluorescent flow cytometry method on Sysmex cell counter.  Material and method: Whole blood from 147 donors were processed in the Reveos automated blood processing system into the separate components. All the interim platelet units received a platelet yield index from Reveos. A sample from each interim platelet unit was collected and analyzed on Sysmex in the channel for fluorescent flow cytometry. Result: The difference between the platelet count from the two methods was 45 ±26 x109/unit (p<0,001). Platelet yield index from Reveos was 67 ±17 x109/unit and the platelet count from Sysmex was 112 ±35 x109/unit. The r2 from the scattergram was 0,49. Conclusion: The platelet yield index from Reveos underestimates the platelet yield compared to fluorescent flow cytometry from Sysmex. The limit for the total platelet yield in a pool of interim platelet units could therefore be decreased.