|Objective To evaluate the effect of hyaluronan-rich transfer medium on pregnancy and implantation rates in fresh and frozenthawed embryo transfers in Korean women with previous implantation failure. Methods This retrospective study included 283 blastocyst transfers in patients with previous embryo transfer failure at a private fertility clinic. In the study group (n=88), blastocyst transfers were performed using an hyaluronan-rich transfer medium prior to transfer, whereas blastocyst transfers without any treatment served as controls (n=195). According to the type of transfer (fresh elective or frozen-thawed), all the blastocyst transfers were divided into two study and two control groups. Results The patient’s mean age, serum anti-Mullerian hormone level, causes of infertility, embryo quality, and the number of transferred embryos were comparable between the study and control groups. There were no significant differences in clinical pregnancy rate (45.5% vs. 43.1%), implantation rate (28.9% vs. 28.8%), and clinical abortion rate (10.0% vs. 8.3%) between the two groups, and these findings were not changed after subgroup analysis according to the type of transfer. Conclusion The use of hyaluronan-rich transfer medium in the blastocyst transfer does not appear to have any significant effect on the implantation and pregnancy rates in patients with previous implantation failure.