Background & Objectives : In spite of effective advances in diagnosis and management, ST Elevation Myocardial Infarction (STEMI) is a major health problem in industrialized world and an increasingly important problem in developing countries. Considering the role of age and gender in Myocardial Infarction (MI) and socioeconomic and cultural changes in Iran in recent decades which can affect the epidemiology of the disease, we aimed to determine trend of changes in age and gender of patients with first STEMI in recent decade.
 Methods :This observational cross-sectional study was based on completing check lists for patients with first STEMI in Rasul-e-Akram Hospital from 1998 to 2007. The Data were analyzed with ANOVA, chi2 and Mann-Whitney tests at = 0.05 using SPSS 14.
 Results :Out of 1829 patients with first STEMI, 76.4% were men and 23.6% women who had mean age of 59.09 ± 12.7 years totally. The mean age of men (56.9 ± 12.2 years) was significantly lower than women (66.1 ± 11.6 years) (p < 0.001) Â.
 Trend of change in mean age for men, women and overall had no specific patterns of change in 10 years. Premature MI occurred in 15% of patients without any particular change during study period. No statistically significant change in proportions of gender and risk factors was seen in a period of 10 years. The most common risk factors were smoking (43.7%) and hypertension (32.8%) respectively. 23 . 7% of patients had hyperlipidemia and 18.8% were diabetics.
 Conclusion: Trend of changes in age and gender of mentioned patients had no significant change over 10 years which can indicate main role of biologic factors. Although this was an observational study unchanged major risk factors in a decade may mark out inadequate primary prevention.
