OBJECTIVE: To compare the effectiveness of letrozole and clomiphene citrate (CC) in patients with anovulatory infertility. DESIGN: Open, prospective, randomized, parallel group, multicentric, comparative trial. SETTING: Out patient clinics of infertility centers in India. PATIENT(S): Fifty-five patients with anovulatory infertility were recruited. Twenty-seven patients (59 cycles) were given letrozole and twenty-eight patients (68 cycles) were given CC. Both drugs were given orally on days 3-7 of menstrual cycle. INTERVENTION(S): Letrozole, CC, ovulation induction, vaginal micronized progesterone, IUI.

MAIN OUTCOME MEASURE(S): Occurrence of ovulation, endometrial thickness and pregnancy rates.

Inclusion Criteria:

• Females with anovulatory infertility 20-38 years of age.
• Diagnosis of anovulatory infertility as established by standard criteria.
• Normal Pelvic USG and bilateral tubal patency
• Willingness and giving written Informed Consent.

Exclusion Criteria:

• Uterine and adnexal pathology e.g. leiomyomata
• Ovarian cyst
• Hyperprolactinaemia
• Hyperthyroidism or Hypothyroidism*
• FSH >9mIU/ml (during early follicular phase).* (As per Chemoluminescence method)
• Previous surgery related to genital tract as per history
• Appendicitis, peritonitis, genital tuberculosis as per history and/or having an abnormal pelvic anatomy
• Impaired hepatic /renal function
• Diabetes mellitus/Random blood sugar- > 140mg/dl
• Drugs likely to interfere with ovulation
• Alcohol intake as per history
• History of hypersensitivity to the study drug or to its excipients
• Planned travel outside the study area for a substantial portion (>5 days) of the study period by potential participants
• Lack of willingness to give informed written consent
• Participation in any clinical study within the preceding 1 month