Background: We investigated the levels of insulin-like growth factor-1 (IGF-1) in acute myocardial infarction (AMI) patients, and we determined whether a decrease in IGF-1 could influence long-term prognosis.Methods: In total, 65 patients who were admitted to our hospital for AMI and 25 healthy controls were included in this study. Fasting blood samples were obtained from all patients immediately after AMI and 10 months later to determine their IGF-1 and insulin-like growth factor binding protein-3 (IGFBP-3) levels. Fasting blood samples were obtained from the control group. The patients were also evaluated for cardiac events 10 months after AMI.Results: The IGF-1 levels were higher in the AMI patients than in the healthy controls (p=0.002); after 10 months, both the IGFBP-3 and IGF-1 levels were higher. No differences were found in cardiac event occurrence between patients with low and high IGF-1 and IGFBP-3 levels (for both the baseline and 10-month values).Conclusions: The serum total IGF-1 and IGFBP-3 levels were higher in the AMI patients compared to the control patients; however, there was no correlation between the IGF-1 and IGFBP-3 levels and cardiac events during the 10-month period after AMI. Additional studies are needed to clarify the time required for IGF-1 and IGFBP-3 level normalization after AMI, and to determine the effects of IGF-1 and IGFBP-3 on the long-term prognosis of patients after AMI.