The use of nonurologic tissues in the genitourinary tract is common (owing to a lack of a better alternative) despite the known possible adverse effects. Selective cell transplantation is providing a means to engineer genitourinary tissues that may be used for reconstruction. This novel technology involves an interdisciplinary approach, combining techniques of cell. biology and materials sciences towards the development of functional tissues or organs. Tissues associated with urology, such as clitoral, cavernosal, urethral, vesical, ureteral, and renal have been created in the laboratory, with varying degrees of function. Cells have also been recently used in patients as bulking agents for the treatment of vesicoureteral reflux and urinary incontinence. As the science of tissue engineering evolves, one can expect a wider application of this technology to the armamentarium of urologic surgery.