After transplantation of nonrenal solid organs, an acute decline in kidney function develops in the majority of patients. In addition, a significant number of nonrenal solid organ transplant recipients develop chronic kidney disease, and some develop end-stage renal disease, requiring renal replacement therapy. The incidence varies depending on the transplanted organ. Acute kidney injury after nonrenal solid organ transplantation is associated with prolonged length of stay, cost, increased risk of death, de novo chronic kidney disease, and end-stage renal disease. This overview focuses on the risk factors for posttransplant acute kidney injury after liver and heart transplantation, integrating discussion of proteinuria and chronic kidney disease with emphasis on pathogenesis, histopathology, and management including the use of mechanistic target of rapamycin inhibition and costimulatory blockade.