BACKGROUND The aim of this study was to determine the effect of Ramadan fasting on fetal growth and Doppler in-dices of pregnancy. METHODS Fifty two healthy pregnant women of second or third trimester, 25 in fasting group and 27 in non fasting group were included. Growth parameters including biparietal diameter (BPD), femoral length (FL), abdominal circumference (AC), estimated fetal weight, amniotic fluid index and also Doppler indices of both uterine and umbilical arteries (including peak systolic and end diastolic velocity, systolic to diastolic ratio, resistive and pulsatility indices) were evaluated by Gray scale and colour Doppler imaging for each women two times, in the beginning and at the end of Ramadan. RESULTS Increases in BPD, FL, AC and fetal weight within one month were similar in two groups. Amniotic fluid index also were similar in two groups. There was not any statistically significant difference in abnormal Doppler indices of uterine or umbilical artery between two groups. CONCLUSIONS The results of present study show that Ramadan fasting has no adverse effect on fetal growth, amniotic fluid volume or maternofetal circulation.