Reabsorption of glucose in the proximal renal tubule involves the Na(+)-coupled glucose cotransporter (SGLT) and the facilitative glucose transport (GLUT) multigene glucose transport families. Mutations in SLC5A2, the SGLT2 coding gene, are responsible for familial renal glucosuria (FRG), a genetic disorder characterized by glucosuria in the absence of both hyperglycemia and generalized proximal tubular dysfunction. In this paper we focus on FRG and describe other inherited and acquired clinical conditions associated with glucosuria. In addition, a brief review on the regulation of renal glucose transport in diabetes is provided.