PYELONEPHRITIS is a common and often severe complication of diabetes mellitus. It is generally believed that pyelonephritis occurs more frequently among diabetic than among nondiabetic persons.1 2 3 Unfortunately, most of the analyses of the relation of diabetes to susceptibility to infection of the urinary tract are obtained from hospital and autopsy experiences. From these studies, it cannot be determined whether diabetic patients are intrinsically more susceptible to infection, or whether they have more infections of the urinary tract because they are more likely to have been catheterized, or in other ways to have undergone instrumentation, or whether coincident bladder dysfunction or . . .