Objective: To determine whether or not endometrial thickness, echogenic pattern and E2/P ratio measured on the day of embryo transfer can serve as reliable predictors of treatment outcome following ICSI/ET cycles. Methods: A total of 367 infertile women undergoing embryo transfer after ICSI cycles were studied in a prospective study. Ultrasound measurement of endometrial thickness on the day of hCG administration and on the day of ET and E2/P ratio on the day of embryo transfer, hormonal prole (Day 3 FSH, LH and E2), and various other variables (age, BMI, number of oocytes retrieved per patient, fertilization rate, number and quality of embryos) were evaluated. These variables were compared among the clinical pregnancy, chemical pregnancy and non-pregnant groups. Also, their inuence on implantation rate was examined. Results: There was no statistically signicant difference in the measured endometrial thickness on the day of hCG administration (10.67 ± 2.25, 10.59 ± 2.18, 10.56 ± 2.22, P = 0.5) and that measured on the day of embryo transfer among the three groups. The distribution of patients with type A endometrium among the clinical pregnancy Vs the chemical pregnancy group (p=0.9) and that among the clinical pregnancy group Vs the non-pregnant group (p=0.14) was statistically insignicant. The E2/P ratio was calculated and compared among the three groups, however the difference was statistically insignicant (78.08 ± 85.27, 51.86 ± 44.81, 110.57 ± 274.49, p=0.65). Conclusion: Ultrasonographic features of the endometrium (thickness and echo-pattern) and E2/P ratio cannot be used as reliable markers for endometrial receptivity in the clinical setting. ABSTRACT KEYWORDS : Endometrial thickness, ech