['Recent advances in technology have made it possible to record various platelet indices. There have been many reports about platelet indices and platelet disorders. The aim of this study is to investigate whether anatomical indices have a correlation with functional aggregation responses using optical method in healthy adults and to evaluate the predictive significance of platelet indices over platelet aggregation responses.', 'This study was carried on 31 adults whose ages ranging between 20 and 42. Platelet parameters, including platelet count, mean platelet volume, platelet distribution width and plateletcrit were determined in platelet rich plasma using Abbott Cell-Dyn 4.000. Platelet aggregation was induced by adenosine diphosphate, collagen and epinephrine. Optical aggregation was performed using a turbidometric method.', 'We have observed no correlation between any of platelet indices measured and platelet aggregation responses.'] Do platelet count , mean platelet volume , platelet distribution width , and plateletcrit correlate with optical platelet aggregation responses in healthy volunteers?