Abstract INTRODUCTION: Myocardial infarction (MI) is the leading cause of mortality and morbidity both in men and women. Risk factor profiles vary in different ethnic groups, in male and female and in different age groups. This study aimed to evaluate the cardiovascular risk factors in young women with AMI, and to compare it with other age and sex groups, in Birjand, south Khorasan. METHODS: This descriptive analytic study evaluated the prevalence of classic CHD risk factors in female patients with acute Myocardial Infarction (AMI) aged ≤ 56 and compared it with female AMI patients aging more than 56 and also with the male patients with AMI. The study group included 311 consecutive female patients (48 patients ≤ 56 and 263 > 56 years old) out of 1112 patients who were hospitalized with acute myocardial infarction in Vali Asr hospital, the referral hospital in the capital of south Khorasan province in eastern Iran, from 2002 to 2006. RESULTS: Diabetes was detected to be the most frequent coronary risk factor in younger women (35.4%). The overall prevalence of diabetes was 22.6% in women with AMI. Women with premature coronary artery disease were found to have a higher prevalence of diabetes compared to older women (35.4% versus 20.1% respectively, P < 0.01). Furthermore, the number of diabetics was significantly higher in women than men (29.2% versus 13.9% respectively, P < 0.001). In addition, number of diabetics was significantly higher in younger women than younger men (age =< 56) (35.4% versus 13.3% respectively, P = 0.03). Hypertension was second most common modifiable risk factor in younger female group and the most common risk factor in older female group. Cigarette smoking was found to be the least common risk factor in the younger female group but the most common, in the younger male. The mean age of female MI patients was only 5.6 years more than male MI patients, which is less than the 10 years delay of MI in females reported in the literature. CONCLUSION: Our findings show a significantly higher prevalence of diabetes in young females compared with both older females and younger males with premature MI. The higher prevalence of DM in young females may be associated with the decreasing difference of mean age between female and male patients with MI. This data may be useful in directing primary and secondary preventive measures. Keywords: Myocardial infarction, Diabetes, Females. </p