New-onset diabetes after transplantation (NODAT) contributes to the risk for cardiovascular disease and infection, reducing graft and patient survival. For improvement of the outcome of kidney transplant recipients, it is of great interest to know precisely the risk factors that contribute to NODAT development. Nonmodifiable risk factors for development of NODAT are age, race, genetic background, family history of diabetes, and previous glucose intolerance. Modifiable risk factors are obesity and overweight, hepatitis C virus and cytomegalovirus infections, and immunosuppressive drugs. Both steroids and calcineurin inhibitors influence the appearance of NODAT, whereas the role of sirolimus in glucose metabolism currently is controversial.