Objective: To evaluate the effect of short coasting, by withdrawing both gonadotropins and GnRH agonist (GnRHa), on the prevention in severe ovarian hyperstimulation syndrome(OHSS) without compromising pregnancy outcome. Method: Thirty-seven women who had been coasted during COH for IVF were coasted when $geq$20 follicles > 15 mm with serum E$_2$ level of 4,000 pg/ml were detected. Coasting was initiated for one or two days depending on the status of follicle on ultrasound and serum E$_2$ level. Both gonadotropin and GnRHa were withheld for coasting. Retrospective study was carried and changes of serum E$_2$ levels, number of oocytes retrieved, fertilization rate, pregnancy rate were compared and analyzed. Results: The mean serum E$_2$ level fell from 6,993 pg/ml on the onset of coasting to 3,396 pg/ml on the day of hCG administration. The mean number of oocytes retrieved and fertilization rate were 15.7 and 70.0%, respectively. Fifteen patients were pregnant (40.6%) and implantation rate was 15.2%. Twenty-six (70.3%) patients were coasted for one day and 11 (29.7%) were coasted for two days. The mean decrease rate of serum E$_2$ level was 43% in one day coasting group and 15% (1$^{st}$ day) and 81% (2$^{nd}$ day) in two day coasting group. The pregnancy outcome was similar between the two groups. After coasting, no severe or moderate OHSS occurred in any patients and mild OHSS occurred in 3(8.1%) patients. Conclusions: Coasting for one or two days can be used successfully in the prevention of OHSS without compromising IVF cycle outcome.