Kidney transplantation is at present the only definitive treatment for patients with end-stage kidney disease that can improve the quality of life compared with dialysis. However, donor organs are of limited availability. The question is whether kidney tissues can be engineered to provide renal replacement therapy. In this Review, we outline key challenges in renal replacement and examine the clinical potential, current limitations and ethical considerations of bioengineering approaches aimed at replacing renal function, including kidney decellularization and recellularization, ex vivo kidney engineering, xenotransplantation, blastocyst complementation and kidneys derived from pluripotent stem cells. Finally, we highlight key hurdles that remain to be addressed to translate bioengineered kidney approaches to the clinic, including product scalability, ex vivo tissue preservation and good manufacturing practice. Renal function can be replaced by bioengineered kidney tissue. This Review discusses in vivo kidney engineering, xenotransplantation, blastocyst complementation and stem-cell-derived kidney tissue engineering as approaches for renal replacement therapy.