Background: Platelet transfusion leaves many problems and controversies such as short storage times, high risk of contamination, poor therapeutic response and often results in transfusion reactions. Transfusion reactions are associated with platelet storage lesion. Increased storage lesions will increase the biological response modifiers such as soluble cluster of differentiation 40 ligand (sCD40L). Soluble CD40L is associated with febrile, allergic and TRALI transfusion reactions. Given the negative impact of sCD40L, it is essential to analyze the level of sCD40L in platelets. Methods: This type of research was an analytical observational study. Samples were 10 thrombocytes of whole blood and apheresis on the first, second and third days of storage. Two milliliters of the product was centrifuged and plasma sCD40L was examined using the BioVendor ELISA method. Data were analyzed using the SPSS version 25 software. Results: The mean sCD40L level in thrombocyte apheresis based on storage times were 4.36Â±1.34 ng/mL (Day-1), 6.87Â±1.75ng/mL (Day-2), and 7.27Â±2.21 ng/mL (Day-3), while the mean sCD40L level in whole blood thrombocyte were 8.36Â±3.77 ng/mL (Day-1), 9.42Â±2.58 ng/mL (Day-2) and 11.10Â±4.02 ng/mL (Day-3). There were no significant differences in storage times in both groups (P>0.05). However, the mean sCD40L level in thrombocyte whole blood tended to be higher than the mean sCD40L level in thrombocyte apheresis. There was a significant positive correlation between storage times and sCD40L levels in the thrombocyte apheresis group (r = 0.549; P <0.05). ANOVA test suggested a statistically significant difference between storage times in TC Apheresis (P < 0.05). Conclusion: The mean sCD40L level in whole blood thrombocyte was higher than thrombocyte apheresis. There was a significant positive correlation and a statistically significant difference between storage times and sCD40L levels in thrombocyte apheresis.