We investigated the effect of uterine artery blood flow on recurrent pregnancy loss. One hundred and twelve patients admitted to our clinic were included in the prospective study. The study group consisted of 28 cases with a history of three miscarriages before the 20th gestational week, and the control group consisted of cases with at least one prior live birth without any history of miscarriage or poor obstetric outcome. The mean pulsatility index (PI) , resistance index (RI) and systolic/diastolic ratio (S/D ratio) values of the uterine artery were measured between the 18th and 23rd days of the menstrual cycle via transvaginal Doppler ultrasonography. No statistically significant difference could be detected regarding uterine artery PI (p = 0.703), RI (p = 0.333), and S/D (p = 0.403) values between the study group and the control group (p > 0.05). In order to clearly determine etiologic causes of recurrent pregnancy loss, new randomized and controlled clinical trials with large patient populations are needed.