It has been reported that use of the free dermal fat graft (FDFG) technique produces a good cosmetic outcome for breast cancer. An FDFG is harvested from the lower abdomen as a columnar-shaped specimen and implanted into the defect of the breast after a partial mastectomy as a volume replacement technique. In this report, two patients who underwent breast-conserving surgery with immediate reconstruction using an autologous FDFG are described in order to show the difference in status between one case with and one without blood flow in the graft. To assess the benefit of this technique using FDFGs, their cosmetic satisfaction was evaluated using a questionnaire, graft shrinkage was measured by CT, and blood flow was assessed using contrast-enhanced ultrasound (CEUS). Both patients scored 10 of 12 points on the questionnaire. After 2 years, shrinkage of the grafts was 21.6 and 25.2 %, respectively. Although one patient had no blood flow in the center of the graft, the other had blood flow from the pectoralis major muscle to the center of the graft. While satisfaction and graft shrinkage were similar in the two patients, one case showed blood flow and had a somewhat softer graft than the other. The graft status was maintained with a good cosmetic outcome for 3 years after breast-conserving surgery with immediate reconstruction using an autologous FDFG, despite mild shrinkage and hardness of the graft. It is notable that blood flow was observed into the graft on CEUS, and more distinct perfusion was seen in the softer graft case after more than 3 years.