Some of the cases of preterm delivery are eligible for intervention therapy. This led to search for a method that can reliably predict the occurrence of preterm birth. The use of ultrasound has been suggested and studied extensively for this purpose. In this study, 75 pregnant women at 22 – 24 ws gestation were selected. 50 high-risk women for preterm delivery and 25 low –risk women. The cervical length in these 75 women was measured using transvaginal and transabdominal ultrasound. This study showed that cervical length was more easily and more accurately measured using TVS, that women with shorter cervices delivered preterm more frequently, and that a cutoff point of 30mm seemed to be appropriate.