Ovarian hyperstimulation syndrome (OHSS) is a complication of assisted reproductive treatments such as in vitro fertilization (IVF). The pathophysiology of severe OHSS includes a humorally mediated capillary leak syndrome that is predominantly centered on the intra-abdominal space. Severe OHSS is frequently complicated by acute kidney injury (AKI), which can be due to any of a variety of mechanisms, each requiring a different management strategy. Mechanisms of AKI in severe OHSS include intravascular volume depletion, kidney edema due to capillary leak, intra-abdominal hypertension or compartment syndrome, and obstructive uropathy due to ovarian enlargement.