The main objective of the study was to find out prevalence of depression and anxiety symptoms in the population of patients with AMI with ST-segment elevation (STEMI), treated with primary PCI (pPCI). Secondary target indicators included the incidence of sleep disorders and loss of interest in sex. The project enrolled 79 consecutive patients with the first AMI, aged <80 years (median 61 years, 21.5% of women) with a follow-up period of 12 months. Symptoms of depression or anxiety were measured using the Beck Depression Inventory II tests (BDI-II, cut-off value ≥14) and Self-Rating Anxiety Scale (SAS, cut-off ≥ 45) within 24 hours of pPCI, before the discharge, and in 3, 6 and 12 months). Results with the value p<0.05 were considered as statistically significant. The BDI-II positivity was highest within 24 hours after pPCI (21.5%) with a significant decline prior to the discharge (9.2%), but with a gradual increase in 3, 6 and 12 months (10.4%; 15.4%; 13.8% respectively). The incidence of anxiety showed a relatively similar trend: 8.9% after pPCI, and 4.5%, 10.8% and 6.2% in further follow-up. Patients with STEMI treated by primary PCI have relatively low overall prevalence of symptoms of depression and anxiety. A significant decrease in mental stress was observed before discharge from the hospital, but in a period of one year after pPCI, prevalence of both symptoms was gradually increasing, which should be given medical attention.