With better understanding of the nature of renal disease and its treatment, many more adolescents are now allowed to participate in recreational and competitive sports. The positive physiologic and psychological effects of exercise are increasingly being appreciated in adolescents with chronic diseases. This article reviews relevant aspects of renal disease that have implications for sports participation by adolescents, including hematuria, proteinuria, hyponatremia, hypertension, solitary kidney, exercise-related acute renal failure, and chronic/end-stage renal disease. It also reviews the renal effects of creatine and protein supplementation in athletes.