Objective: The aim of the present study was to examine the levels of insulin-like growth factor (IGF-I) and binding protein-3 (IGFBP-3) in acute coronary syndrome (ACS) and their relationship with prognosis. Materials and Methods: Thirty patients with ACS (22 male, 8 female) were included in our study. Patient’s population included 20 patients with ST elevation myocardial infarction (STEMI) and 10 with non-ST-elevation ACS. Death, re-infarction, revascularization and malignant arrhythmia were monitored during 3 months. Study group was compared with 20 healthy subjects (Controls). Blood samples were collected in the first 24 hours and at the end of third month. Serum IGF-I and IGFBP-3 levels were determined by radioimmunoassay method. Results: We found decreased level of IGF-I only in the STEMI group (105±84 ng/ml vs. 715±150 ng/ml, p<0.0001). There were no significant differences in IGFBP-3 levels between two groups. Serum IGF-I levels were significantly increased after 3rd month in the STEMI group (356±72 ng/ml vs. 105±84 ng/ml, p=0.025). There was no relationship between IGF-I, IGFBP-3 levels and cardiovascular events occurred during 90 days of follow-up. Conclusion: These data allows to suggest that significantly decreased level of IGF-I in STEMI group of ACSs can be used as a marker of myocardial necrosis. There was no relationship between IGF-I level and cardiovascular events occurred in 90 days, so this parameter can not be used as a negative prognostic factor.