Background: Albumin modified by Amadori glucose adducts contributes to the pathogenesis of complications of diabetes and reducing its formation ameliorates their development, underscoring the need for accurate information on the rate of formation of this biologically active glycated protein. However, this subject has not been examined in over two decades, and there is reason to question data in older reports. Methods: The present study used nonradioactive and nonreductive techniques to examine the rate of formation of glycated albumin and compare it to that of glycohemoglobin, using a sensitive and specifi c immunoassay for measurement of the stable glucose adduct formed after incubation of serum, plasma and purifi ed albumin with glucose. Results and Conclusions: We report that the rate of formation of glycated albumin parallels that of glycohemoglobin at approximately 0.005-0.008 percent per mM glucose per day, refuting values from the older literature and providing clinically relevant information concerning levels of glycated albumin in diabetes and of treatment directed at reducing its formation.