Ovarian hyperstimulation is an iatrogenic syndrome that presents as the most serious complication of ovarian induction. This syndrome is characterized by bilateral multiple cysts and third space fluid distribution. While mild forms have no consequences to the patient, severe forms may result in mortality and severe morbidity. A new classification of the syndrome is proposed based on the severity. The classification should guide the fertility specialist in determining the plan of management. OHSS is most prevalent in patients with polycyctic ovarian syndrome. Prediction depends on the clinical acumen and careful monitoring using ultrasounagraphy and serum estradiol measurements. The most popular method for prevention is coasting. The role of dopamine agonists has become part of the standard management. The management of OHSS could be achieved on an outpatient basis in many circumstances. Correction of the circulatory volume and the prevention of thromboembolism are the two basics that should be achieved by all clinicians involved in the management of the patient.