1. The glomerular sialic acid content of kidneys from diabetic subjects, aged subjects and healthy young individuals was determined.
2. Similar mean sialic acid contents were found in the glomeruli of elderly diabetic subjects, and in age- and sex-matched non-diabetic subjects.
3. Higher mean sialic acid content was found in glomeruli from healthy, young non-diabetic subjects.
4. These results, in conjunction with other reported work, indicate that low sialic acid content may result from both diabetic and age changes in the glomeruli.