The article presents the analysis of clinical and angiographic characteristics and risk factors of myocardial infarction (MI) in men and women aged <45 years. The study included 35 patients with acute MI (15 females, 20 males) of the 14th Department of Cardiology, N. I. Pirogov City Clinical Hospital No. 1 (Moscow). The average age of female and male patients was 41.2 and 39.6 years, respectively. The majority of patients of both sexes had ST-elevation MI (STEMI) (88.6 %), among which Q-wave MI accounted for 60.0 % of cases and typical MI accounted for 71.4 % of cases. Forty percent of patients of both sexes had no previous history of CHD. Almost all risk factors (dyslipidemia, hypertension, early family history etc.) were seen more often in women compared to men, except smoking which was found to be a risk factor in 55 % of men vs. 6 % of women (p <0.05). The coronary angiography data showed the prevalence of the right type of coronary circulation (70 % of patients) and single-vessel disease (80 %) with coronary stenosis of more than 75 %. The time to diagnosis was 2.1 times greater in women than in men accounting for an average of 9.2 and 4.3 hours, respectively. The main causes of delayed MI diagnosis before admittance were late patient referral or diagnostic errors.