This study is concerned with relationship between serum level of IGF-1 and heart function in pts with first STEMI treated with primary angioplasty. The prospective study consisted of 50 pts (34 men and 16 women) aged 34-72 yrs (mean 56.3±10.8 yrs) with acute STEMI treated with PCI. Mean follow-up was 102±8days. The heart function was assessed on 1st day of STEMI (Killip classification) and after 3 months follow-up (NYHA classification). Heart function was measured by using echocardiography. The exercise capacity was assessed by cardiopulmonary exercise test. The mean value of IGF-1 concentration was significantly higher 12 hrs after PCI as compared to the mean value obtained 3 hrs after PCI. There were no correlations between IGF-1, IGFBP-3 and CK, CK-MB, TnI. Significant positive correlations were detected between IGF-1 and TAPSE on 3rd day of STEMI, between IGF-1 and LVMI after 3 months follow-up. Moreover significant positive correlations were observed between IGF-1 and VO2peak , and between IGF-1 and VO2(AT) after 3 monts follow-up. The analysis showed in close relationship between type of infarcted coronary artery and heart function. Increase of IGF-1 concentration in acute STEMI treated with PCI by 70 units leads to improvment in NYHA classification by one class after 3 months follow-up and increase of NTproBNP concentration by 2500 units leads to worsening of NYHA classification by one class after 3 months follow-up. Conclusions: the mean value of IGF-1 concentration increases during the 1st day of acute STEMI treated with PCI; IGF-1 is close relationship with heart function and exercise capacity during follow-up.