Objectives: Hepatitis A (HepA) virus is a common infection worldwide that causes inflammation of the liver. Platelet index, particularly plateletcrit (PCT) which shows percentage of blood occupied by platelets, is thought to be potential marker of inflammation. Therefore, we aimed to investigate the changes in PCT percentages during HepA infection. Subjects and Methods: Seventy-three children with a diagnosis of acute HepA infection and 68 age- and sex-matched healthy controls were enrolled in this study. Their values of platelet indices [PCT and mean platelet volume (MPV)] obtained from complete blood counts, which were analyzed by XN-1000 analyzer, were statistically compared with each other. Results: PCT and MPV of the patients were found to be higher than those of controls (8.89 1.30 vs 8.03 0.89 for MPV and 0.29 0.11 vs 0.24 0.05 for PCT; P = 0.000, P = 0.002, respectively). In addition, PCT and platelet counts showed a significant negative correlation with alanine aminotransferase (ALT) levels, which indirectly represents inflammation in the liver (PCT: r = 0.368, P = 0.002; platelet count: r = 0.304, P = 0.009). In contrast, MPV levels were not found to demonstrate any correlation with ALT (r = 0.205, P = 0.082). Conclusion: Both MPV and PCT are capable of reflecting the inflammation during acute HepA inflammation. Also, PCT shows a significant negative correlation with the degree of inflammation.