Background: polycystic ovary (PCO) syndrome is an endocrionologic disorder that affecting about 6-10% of women in their reproductive age. Conception rate with clomiphene citrate treated cycles is about 40% only and the number of ovulated oocyte decrease significantly with repeated cycles of ovulation. Objective: evaluation of the effectiveness of usage of clomiphene citrate with L-carnitine (LC) in induction of ovulation in clomiphene citrate resistant patients. Patients and Methods: Randomized controlled study included a total number of 50 women with clomiphene-resistant PCOs. They were divided into 2 groups, group (A) where patients received 100 to 150 mg clomiphene citrate from day three until day seven of the cycle and L-carnitine (LC) 3g daily till positive pregnancy test and group (B) received 100 to 150 mg clomiphene citrate with placebo. Results: There was statistically significant difference (p-value <0.05) between both groups as regard infertility duration (months), ovulation rate, no. of chemical pregnancies and no. of clinical pregnancies. There was highly statistically significant difference (p-value < 0.001) between both groups as regard days until HCG injection, endometrial thickness (mm), no. of pre-ovulatory follicles >17 mm and E2 on day of HCG injection. Conclusion: Adding L-carnitine to clomiphene from the follicular phase and extending through the luteal phase in patients with clomiphene-resistant PCOS, at the given dose and duration, may be of beneficial to the quality of ovulation and the clinical pregnancy rate.