This investigaion was designed to study the haemodynamic changes in the umbilical artery during normal caprine pregnancy using Doppler ultrasonography. Ten nanny goats were synchronized using 2 intramuscular injections of PGF2a 12 days apart, only six were pregnant. The pregnant goats were examined, between 25 – 125 days of pregnancy, every 5 to 10 days using a combination of two – dimensional real – time ultra – sonography, color Doppler and ppulsed wave Doppler ultrasongraphy. Transrectal scanning was done using a 7 MHz vector transducer between days 25 – 50 of gestation. Thereafter, transabdominal scanning was performed using a 5 MHz linear transducer. After locating the umbilical cord by real – time ultrasonography, the umbilical artery was defined by color Doppler ultrasonography. Pulsatility index (PI), resistance index (RI) and systolic to diastolic (S / D ) ratio in the umbilical artery were measured by using pulsed wave Dopper ultrasonography. The angle of the ultrasound beam to the umbilical artery was 45*. RI and S / D ratio had a significant linear correlation with the gestational age. In conclusion, the resistance to blood flow within the umbilical artery decreases with advancement of caprine pregnancy to match the fetoplacental development.