IIV FSH was administered to eight women with PCOD to induce ovulation. These patients had been previously treated unsuccessfully with CC or IM gonadotropins. The drug was administered by a pump at 120-minute intervals. Dosage was 1 ampule Metrodin (75 IU of FSH less than 0.11 IU of LH)/day. Eight cycles of treatment were effected. With the IIV regimen, ovulation rate was 75% (six cycles). Two multiple pregnancies and one abortion (mola vescicularis) were observed. Preovulatory E2 plasma levels and the number of follicles recruited per cycle varied from 530 to 3800 pg/ml and from 4 to 15, respectively. Maximal follicular diameter was between 16 and 28 mm. LH levels significantly decreased, while FSH levels were unchanged, resulting in a decrease of LH/FSH ratio. It is concluded that the IIV FSH regimen offers an additional modality for the induction of ovulation in PCOD patients. Further clinical trials with alternative regimens are needed, however, to identify the optimal dosage and frequency of administration of the drug.