The importance of routine screening for microalbuminuria in patients with diabetes has gained widespread acceptance. Since shortened collection times and random urine sampling facilitate outpatient testing for patients, it is necessary to establish whether a recent fluid intake might alter test results. Specifically, does an oral fluid load (15 ml/kg) effect urinary albumin excretion in Type I diabetes? Indeed, we show that fluid intake had a significant impact: albumin concentration decreased, whereas the albumin/creatinine ratio (A/C) and albumin excretion rate increased (P<.001) significantly. © 2002 Elsevier Science Inc. All rights reserved.