Background: Nosocomial infections (NI) are common complications after cardiac surgery. Till now, there are rare manuscripts investigating NI in intensive care unit (ICU) after cardiac surgery. Our article was designed to investigate the characteristics of distribution of pathogenic bacteria and antibiotics resistance of NI. Methods: 1360 patients received standard postoperative care including antibiotic prophylaxis. Microbiological examinations of the sputum, blood, catheter tips and excretion were performed as clinically indicated to isolate pathogens. Results: 89 patients (6.54%) acquired microbiological documented NI. There was a statistical difference in mortality between two groups with or without postoperative NI (23.60% vs 2.28%, p<0.00). 98 (73.13%) were isolated from sputum and 32 (23.88%) from blood. 3 (2.24%) SSI were detected (2 superficial SSI, 1 mediastinitis) and only 1 (0.75%) from urine. The most common pathogens were Gram-negative bacteria (78.36%), followed by Gram-positive bacteria (14.93%) and fungi (6.71%). The major species of pathogens had different levels of drug resistance and most of them exhibited multidrug-resistance (MDR). Conclusions: We analyzed the characteristics of distribution of pathogens and antibiotics resistance of NI in our center and provided some suggestions for clinical practice. Except for antibiotic treatment, aggressive infection control measures may be crucial to stop or prevent outbreaks.