Abstract: Objective To assess the predictive value of endometrial ultrasonography and age for the outcome of in vitro fertilization-embryo transfer (IVF-ET).Methods A total of 305 women with tubal occlusion were studied. Superovulation was induced and transvaginal ultrasonography was employed for monitoring the endometrial thickness and endometrial patterns on the day of human chorionic gonadotrophin (hCG) administration. Pregnancy was diagnosed by ultrasonography of the intrauterine gestational sac.Results No difference was noted in the endometrial thickness or endometrial patterns between pregnant and nonpregnant groups, but the least endometrial thickness essential for pregnancy was 7 mm. The pregnant rate of women aged 20-34 years was higher than that of women aged 35 years or above.Conclusions Neither endometrial thickness nor endometrial patterns detected by transvaginal ultrasonography on the day of hCG administration allows a reliable prediction of pregnancy. The least endometrial thickness essential for pregnancy is 7 mm and the pregnant rate of women aged 20-34 years was higher than those aged 35 years and above.