Abstract Introduction and objectives Patients undergoing cardiac surgery can have post-operative complications, including infections. The aim of this article was to study the incidence, severity and risk factors of invasive candidiasis in these patients, based on the hypothesis that several factors (multiple transfusions and time on extracorporeal circulation) are related to invasive candidiasis. Material and methods The study included a prospective analysis of 669 patients undergoing scheduled cardiac surgery from April 2016 to December 2017. Control cultures were collected on admittance to the Surgical Intensive Care Unit. Results The incidence of invasive candidiasis was 2.69%, being confirmed in 1.79% of cases. The most frequently isolated Candida species was Candida auris. Mortality rate in the invasive candidiasis group was 11% in the immediate post-operative period and 22% at 30 days. After the univariate study, a statistically significant relationship was found between invasive candidiasis and multiple transfusions (OR 15.86; 95% CI: 5.15–69.4; p Conclusions Multiple transfusions are associated with an increased risk of invasive candidiasis. Surveillance measures for fungal infection in patients with risk factors undergoing cardiac surgery should be implemented in hospitals with a high incidence of candidiasis.