Obesity or fatness and excess body weight are defined as the accumulation of adipose tissue to an extent harmful to health, and in developed countries they appear on epidemic proportions. Body mass index with a range of desired values, according to the World Health Organization, from 18.5 to 24.9 kg/m2 is widely used to assess the accumulation of adipose tissue. Adipose tissue promotes failed processes that accelerate the development of atherosclerosis, which is the basis of all cardiovascular diseases. Mortality from cardiovascular diseases can be prevented by optimizing body weight. OBJECTIVE OF THE RESEARCH: The main objective was to examine the occurrence of overweight patients and obesity in patients with acute coronary syndrome. DESIGN OF THE STUDY: Retrospective study. METHODS: The data was collected from the Hospital Information System, in the period from January 1, 2020 to April 30, 2021, and the patients admitted to the Merkur Clinical Hospital with a diagnosis of acute coronary syndrome were investigated. RESULTS: The research included 32 subjects with normal body weight and 99 subjects with increased weight. No difference in the number of significant coronary lesions was demonstrated. Patients with an elevated body mass index statistically significantly more often have dyslipidemia. Dyslipidemia and age are associated with a statistically significant higher frequency of multiple coronary lesions. CONCLUSION: Out of the total number of hospitalized patients due to acute coronary syndrome in the examined time period, there were statistically significantly more patients with excessive body weight, but they did not have a greater number of significant coronary stenoses, statistically significantly more often they have dyslipidemia. Prevention of excess body weight is necessary for the prevention of acute coronary syndrome.