Cardiac surgery-associated acute kidney injury (CSA-AKI) is a common complication following cardiac surgery. Despite growing awareness of sexual dimorphism in cardiovascular and chronic kidney disease, little is known about sexual dimorphism in CSA-AKI. In this narrative review, we will first discuss sex differences and the potential role of sex hormones in the CSA-AKI pathophysiology. Women may tolerate hypoperfusion and hypoxia better, have a different neurohumoral response and experience less inflammation and oxidative stress. Next, we discuss the conflicting evidence on the difference in incidences of CSA-AKI between sexes and suggest that female sex might not be a risk factor. Finally, we focus on sex differences in preventative treatment strategies for CSA-AKI. Analysing sex differences in interventional studies is challenging due to the relative minority of women within the cardiac surgery population. Unravelling sex differences can improve personalized medicine and improve future patients’ outcomes, for both sexes.