Introduction: Postoperative infections in pediatric cardiac intensive care units (PCICU) are a challenge for healthcare professionals and a problem for patients and affect their quality of life. Aim: The aim of the study was to investigate postoperative infections in PCICU and specifically to determine the pathogenic microorganisms responsible for them. Material-Methods: This is a systematic review of the literature carried out from 2016 to 2022, with a search for articles using the keywords: “PCICU”, “cardiac surgery”, “nosocomial infection”, “congenital heart disease”, “risk factors” in international bibliographic databases (PubMed, Scopus and Google Scholar) as well as synonyms or combinations of words. The criteria for the inclusion of the articles in the study were: To be written in the English language, to be published in valid scientific journals in the databases PubMed, Scopus, Google Scholar, to concern children in ICU (cardiac surgery or not) after cardiac surgery, to be about the post-operative infections of these children and to mention in them the micro-organisms responsible for these infections. Results: postoperative infections occur in a large percentage of children (>4.7%) who underwent cardiac surgery, while mortality from them ranges from 13.7-35.7%. The most common infections are bloodstream infections (BSI), respiratory tract infections, urinary tract infections and surgical wound infections. The pathogens isolated from these infections are more often Gram(+) pathogens. The most frequent pathogens isolated were Staphylococcus aureus, Streptococcus spp., Candida spp., Escherichia coli, Klebsiella, Acinetobacter, Pseudomonas aeruginosa. The most frequent risk factors for the development of infections are intubation, prolonged duration of mechanical ventilation, length of stay in the PCICU and in the hospital, delayed sternal convergence, urinary catheter and body weight. Conclusions: Postoperative infections in PCICUs are a major problem in these patients, and efforts to address it should focus on greater investigation of reported risk factors.