To assess the predictive value of different clinical, laboratory, and ultrasound parameters in Letrozole when used as an ovulation induction in anovulatory infertile PCOS women. The current study was done in the secondary-referral infertility clinic in AL-Yarmouk teaching hospital, and Al-Mustansiriyah medical college. Sixty-seven anovulatory infertile women with the polycystic ovarian syndrome. Letrozole was given orally on day 2 or 3 of the menstrual cycle for five days and repeated for three consecutive cycles. The primary outcome measures were to evaluate the response rate in the form of successful ovulation and clinical pregnancy. The ovulation rate was (64.2%), with clomiphene naïve vs. previous clomiphene use; it was 87.5%, 51.2% respectively, while pregnancy rate was (32.8%), 41.6% with clomiphene naïve vs. 27.9% with previous clomiphene use. Clinical (age, BMI, Waist circumference, cycle length and days between cycle, infertility period and type, previous reproductive outcome, androgen symptom and m-FG score), laboratory (E 2 , FSH, LH, testosterone, FAI, FBS, fasting insulin, HOMA – IR, and AMH) and ultrasound (mean ovarian volume, mean AFC and antral follicular diameter) parameters were founded to affect ovulation and pregnancy in different extent. After putting all variables in a scoring system, it was found that if the patients had > 26 points for the score, it's more likely that the woman becomes pregnant. A predictive pregnancy score was developed from basic clinical, laboratory, and ultrasound parameters. It may help the clinician to individualized ovulation induction protocol in PCOS women; however, external validation of this system is recommended in a more extensive prospective study.