Background: Clomiphene citrate (CC) is still holding its place as the first-line treatment for induction of ovulation in polycystic ovary syndrome (PCOS) patients.  Objective: to assess the effect of extended clomiphene citrate on pregnancy outcomes of clomiphene resistant PCOS. Patients and methods: this study was conducted on 48 PCO patients with CC resistance attended to the Obstetrics and Gynecology Outpatient Clinic at Menoufia University and Al-Bajour General Hospitals, from April 2018 to February 2020.  Patients were treated with an extended CC administration (150 mg for 10 days) to overcome anovulation. Result: There was highly significant change in follicle-stimulating hormone (FSH), luteinizing hormone (LH) and FSH/LH after extended CC treatment (p < 0.001). Also, serum progesterone and number of follicles were significantly increased after treatment compared to before treatment. Conclusion: CC extended is a safe, effective with minimal side effect, but low pregnancy rate was observed. Therefore, further studies with large number of PCO patients with CC resistant with addition of other drugs are required to investigate the improvement of the pregnancy rate.