The present study entitled, “Transvaginal Sonographic cervical length measurement as predictor of Preterm delivery” was carried out on 150 cases of primiparas who attended the Govt. Medical College, Hospital, Nagpur. The transvaginal ultrasonographic cervical length was measured at 18 -20 weeks. These cases were followed at 24 weeks and 28 to 30 weeks for pregnancy outcome as abortion, preterm labour or full term delivery. The study was carried out to correlate the outcome of pregnancy (preterm delivery) with the transvaginal cervical length measured serially at 18-20 wks, 24 wks & 28-30 wks. The mean cervical length was 41.9 at 18-20 weeks, 40.09 at 24 weeks and 37.41 at 28 to 30 weeks. The mean cervical length in patients who had preterm delivery was 22.67 at 18 to 20 weeks, 24 at 24 weeks and 18.50 at 28-30 weeks compared to 42.03, 40.3 and 32.41 respectively in those who had full term delivery. This difference was significant. The cervical length of