The role of platelets as the initial defense against insult to the vasculature is well established. Moreover, platelets are now recognized as having a critical role in the acute care settings of cardiopulmonary bypass (CPB) procedures and cardiac catheterization. In the environment of CPB, both platelet count and function have been demonstrated as being markedly compromised during and following the procedure. Unfortunately, current assays that are used to evaluate the parameters of platelet count and function are limited in regard to their utility in a near patient format. Here, we describe a practical, rapid, and user-friendly whole blood platelet function assay that has been developed for the ICHOR point-of-care hematology analyzer. This analyzer is capable of performing an eight parameter blood profile including platelet count. In comparable studies, platelet aggregation in whole blood demonstrated good correlation (for ADP the values were n = 14, r2 = 0.81, p = 0.0001; for collagen, n = 10, r2 = 0.93, p = 0.0001; for ristocetin, n = 10, r2 = 0.89, p = 0.0001; and for epinephrine, n = 10, r2 = 0.81, p = 0.0003) with traditional platelet-rich aggregometry, which uses increased light transmission as an indication of platelet aggregation. Furthermore, early feasibility studies in CPB patients demonstrated both decreased platelet count and a marked reduction in platelet function peri-procedurally. This new assay of platelet function is extremely suitable for the clinical environment with rapid turnaround time and provides a full hematology profile to enhance transfusion decisions.