Introduction: Clomiphene citrate (CC) is the first drug used to induce ovulation in patients with poly 
cystic ovary syndrome (PCOS). Although 70–80% of such women ovulate when treated with CC, 
only 40% become pregnant (van Wely et al., 2005). Women who do not ovulate with increasing doses 
of CC are CC-resistant (Amin et al., 2003). So a different modality of treatment for such patients was 
required. Aim of the work: The aim of the present work is to compare the effects of letrozole versus 
gonadotropin for induction of ovulation in patients with polycystic ovary syndrome resistant to 
clomiphene citrate. Patients and Methods: The present study is a randomized clinical trial. The study 
was conducted at infertility clinic of Minia general hospital, Minia, Egypt; throughout the duration of 
18 months from January 2017 to June 2018. Results: Letrozole groups showed a statistically 
significant higher incidence of ovulation compared to gonadotropins group yet no difference in 
pregnancy rate was detected between the two groups. Discussion: Most studies comparing letrozole 
and gonadotropins in women with CC-resistant PCOS were either retrospective or in the context of 
intra uterine insemination presenting the need for studying letrozole versus gonadotropins in the 
context of induction of ovulation and timed intercourse. Summary: Letrozole is a cost effective 
modality for induction of ovulation in patients with PCOS resistant to CC.