The effect of pyelocaliectasis on intrarenal arterial Doppler indices was evaluated in healthy pregnant women with respect to nonpregnant controls. There was no significant difference between the pregnant and nonpregnant subjects regarding the systolodiastolic ratio, resistivity index and pulsatility index throughout the second and third trimesters (p for all > 0.05). There were 134 kidneys with grade 0, 38 kidneys with grade I and 24 cases with grade II pyelocaliectasis in the pregnant population. Grade II caliectasis was found only in the right kidneys. The nonpregnant women all had grade 0 caliectasis. Doppler indices were not significantly different in various grades of caliectasis, and right and left kidneys had similar Doppler indices. The results of this study suggest that pyelocaliectasis increases with advancing gestational age and is more frequent and prominent on the right side but has no effect on intrarenal Doppler indices in healthy pregnant women. In cases of prominent alterations in Doppler indices, renal pathological conditions should be sought.