Ultrasound guided embryo transfer (UGET) is now widely accepted as the preferred method for embryo transfer (ET). However, we still do not know which parameters may be related to success rate when performing UGET. Our study is aimed to examine whether parameters such as uterine position, bladder fullness, quality of imaging and level of difficulty in performing ET are related to pregnancy rates. Retrospective, observational study. In 873 UGET of fresh (785 ET) or frozen (88 ET) embryos performed only by highly experienced IVF physicians we collected data regarding the ET process. The performing physician summarized the data regarding: uterine position (anterior, middle or posterior), bladder fullness (full, empty or partially full), imaging quality (good, moderate or bad), difficulty during embryo transfer (easy, moderate, difficult), blood on catheter (yes or no). We evaluated the correlation between these parameters and pregnancy rates. Pregnancy rates did not differ when comparing uterine position, (33.6%, 38.2% and 30.9% for anterior, middle and posterior positions respectively) bladder fullness (32.8%, 34.6% and 33.1% for full, empty and partially full bladder respectively), imaging quality (33.2%, 34% and 32.3% for good, moderate and bad imaging quality respectively) and difficulty performing ET (33.3%, 36% and 30.4% for easy, moderate and difficult transfer respectively). The only parameter showing a tendency to affect pregnancy rates was the finding of blood on the transfer catheter (26.1% vs. 34.5% for presence or absence of blood on catheter respectively). We did not find a significant correlation between the parameters of bladder fullness, uterine position, quality of imaging and level of difficulty and pregnancy rates. The only parameter that had a tendency to lower pregnancy rates was the finding of blood on the transfer catheter.