Mild forms of ovarian hyperstimulation syndrome (OHSS) do not require treatment. Moderate OHSS should be followed up on an outpatient basis with no specific treatment. Severe OHSS requires proper evaluation. Investigations are done to evaluate hematocrit, electrolytes, and kidney and liver function. Conservative treatment with intravenous (i.v.) fluids and close monitoring is usually done. Intensive care admission is indicated in cases with severe respiratory distress or major electrolyte imbalance with elevated serum creatinine. Crystalloids in the form of i.v. saline and colloids as albumin or hydroxyethyl starch are commonly used to expand intravascular volume. Dopamine can be used to improve diuresis, and prophylactic heparin is administered to prevent venous thrombosis. Diuretics are generally contraindicated because they may further contract intravascular volume. Abdominal or vaginal aspiration of ascitic fluid results in marked improvement of symptoms, improved diuresis, and shortened hospital stay. The current trend to treat patients with i.v. fluids, albumin, and to perform aspiration of ascitic fluid on an outpatient basis has been found to be a more cost-effective protocol of treatment.