Background: Obesity is becoming more prevalent in the end-stage renal disease population. Bariatric surgery (BS) is increasingly considered as an approach to become eligible for kidney transplant (KT) or reduce obesity-related morbidities.

Objectives: To assess the short- and long-term outcomes of patients who underwent both BS and KT and to determine the optimal timing of BS.

Methods: Patients who underwent both KT and BS between January 2000 and December 2020 were included and stratified according to the sequence of the 2 operations. The primary outcomes were patient and graft survival. The secondary outcomes were postoperative complications and efficacy of weight loss.

Results: Twenty-two patients were included in the KT first group and 34 in the BS first group. Death uncensored graft survival in the KT first group was significantly higher than in the BS first group (90.9% versus 71.4%, P 5.009), without significant difference in patient survival and death-censored graft survival (100% versus 90.5%, P 5 .082; 90.9% versus 81.0%, P 5 .058). There was no significant difference in 1-year total weight loss (1-yr TWL: median [interquartile range {IQR}], 36.0 [28.0–42.0] kg versus 29.6 [21.5–40.6] kg, P 5 .424), 1-year percentage of excess weight loss (1-yr %EWL: median [IQR], 74.9 [54.1–99.0] versus 57.9 [47.5–79.4], P 5.155), and the incidence of postoperative complications (36.4% versus 50.0%, P 5 .316) between the KT first and BS first groups.

Conclusion: Both pre- and posttransplant BS are effective and safe. Different conditions of each transplant candidate should be considered in detail to determine the optimal timing of BS.