Purpose: Free flaps play an important role in the reconstruction of chronic wounds in the lower extremities. Nonetheless, the use of free flaps for chronic wound reconstruction tends to be challenging. A considerable number of patients with chronic wounds have noteworthy medical histories, such as chronic kidney disease or end-stage renal disease (ESRD). This study aimed to determine the relationship between the success rate and complications of free flap surgery according to the degree of kidney disease from normal renal function to ESRD.Methods: A retrospective study of all patients who underwent free tissue transfer procedures due to chronic wounds in the lower-extremity area over a 9-year period, between October 2011 and February 2020, was conducted. The primary outcome was flap failure, and major complications were set as the secondary outcome.Results: Sixty-seven consecutive free flaps were used for chronic wounds of the lower extremities at our institution. Flap failure occurred in six patients (9.0%), resulting in a total flap survival rate of 91.0%. Sixteen patients (23.9%) experienced major complications. Flap failure was correlated with the presence of ESRD and renal transplantation. Conclusion: There are several limiting factors for the reconstruction of chronic wounds in the lower extremity. In particular, ESRD and renal transplantation were significantly correlated with flap failure.