Aims: To determine prevalence of intrahospital infections in cardiosurgical patients admitted to the Intensive Care Unit (ICU) of The Clinical Hospital Centre Rijeka in period from January 6th, 2014 to December 29th, 2014; to determine the incidence of infections compared to patient's sex, to classify most common pathogens, to determine the outcome, to determine the incidence of infections compared to the outcome and specify most used antibiotics in treatment process. Patients and methods: This retrospective study comprised 335 cardiosurgical patients with hospital-acquired infection treated in the cardiosurgical ICU of Anesthesiology, Reanimatology and Intensive Therapy Clinic of The Clinical Hospital Center Rijeka in the period from January 6th, 2014 to December 29th, 2014. Results: Out of 335 patients treated in the cardiosurgical ICU during the research period, 26 (8%) of them acquired an infection. No statistically significant result was attained comparing incidence of infections to patient's sex. The most common pathogens were Pseudomonas aeruginosa, bacteria genus Enterobacter spp., Klebsiella spp., Escherichia. Coli, Proteus spp., Enterococcus spp. and yeast genus Candida spp. 26 patients acquired an infection during their ICU stay and 8 (31%) of them died. Lethal outcome had 22 (7%) out of 335 patients in total. Statistically significant result was attained when comparing incidence of infections to outcome. Conclusion: Approximately 8% of cardiosurgical patients acquire an infection in the early postoperative period in ICU on a yearly basis. No statistically significant difference was attained regarding gender distribution. Gram-negative bacteria was the most common cause of the infections. Of all patients who acquire intrahospital infection, rougly one third ends in fatal outcome. There was found statistically significant difference which testifies to association of incidence with fatal outcome.