Surgical site infections (SSI) are common healthcare-associated infections. SSIs after kidney transplantation (K-Tx) can endanger patient and allograft survival. Multicenter studies on this early post-transplant complication are scarce. We analyzed consecutive adult K-Tx recipients enrolled in the Swiss Transplant Cohort Study (STCS) that received a K-tx between May 2008 and September 2020. All data were prospectively collected with the exception of the categorization of SSI that was performed retrospectively according to the Centers for Disease Control and Prevention criteria. A total of 58 out of 3059 (1.9%) K-Tx recipients were affected by SSIs. Deep incisional (15, 25.9%) and organ/space infections (34, 58.6%) predominated. In the majority of SSIs (52, 89.6%) bacteria were detected, most frequently Escherichia coli (15, 28.9%), Enterococcus spp. (14, 26.9%), and coagulase-negative staphylococci (13, 25.0%). A BMI ≥25kg/m ² (multivariable OR 2.16, 95% CI 1.07-4.34, P=0.023) and delayed graft function (multivariable OR 2.88, 95% CI 1.56-5.34, P=0.001) were independent risk factors for SSI. In Cox proportional hazard models, SSI was independently associated with graft loss (multivariable HR 3.75, 95% CI 1.35-10.38, P=0.011). In conclusion, SSI was a rare complication after K-Tx. BMI ≥25kg/m ² and delayed graft function were independent risk factors. SSI were independently associated with graft loss.