Background: Septic purulent nosocomial infections (SPNI) are one of the most significant healthcare challenges of post-surgical procedures. SPNI are associated with increased morbidity, mortality and admission costs. It is a priority to determine the level of nosocomial infections (NI). This study aims to evaluate the bacterial contaminations after cardiac surgery within the Department of Acquired Heart Defects (DAHD). Material and methods: A cross-sectional study was designed and the medical records of 1189 patients who underwent cardiac surgery within the DAHD of a multiprofile hospital were retrospectively analyzed. The data were collected and stored in a Microsoft Excel spreadsheet. Results: The incidence rate of SPNI following cardiac surgery was 317.57‰ compared to 15.02‰ officially reported (p <0.001). Of the most common infections among the total of 418 cases of SPNI studied, 32.06% were surgical site infections, 23.18% were associations of infections, 19.14% – respiratory tract infections. A patient with SPNI has an average of 22.25 days/bed spent in hospital, compared with the average for a patient without SPNI of 12.27 days/bed. The etiological structure includes 28 species of microorganisms including gram-positive (61.92%) and gram-negative (38.08%). Conclusions: Given the relatively high incidence of the SPNI and its impact, it is imperative to take more serious measures to prevent and control these infections.