We sought to determine whether the clinical setting in which pancreatitis occurs affects the incidence and distribution of increased values of renal clearance of amylase relative to creatinine, CAm/CCr, and whether the increased values reflect a tubular disorder that impairs renal reclamation of certain low molecular weight proteins. We measured the renal clearance of three low molecular weight proteins (amylase, beta 2-microglobulin, and lysozyme) and urinary excretion of three lysosomal enzymes that originate from the renal tubule in three groups of patients (alcoholic pancreatitis, pancreatitis without alcoholism, and alcoholism without pancreatitis). When compared to normal controls, the mean CAm/CCr was significantly elevated in alcoholic pancreatitis (p less than 0.05) but not in equally severe pancreatitis without alcoholism nor in alcoholism without pancreatitis. The clearance ratio of beta 2-microglobulin was significantly increased in each of the three patient groups; mean clearance ratio of lysozyme was not significantly increased in any of the patient groups. Excretion of each of the three lysosomal enzymes was significantly increased in each of the patient groups. We conclude that the etiology of pancreatitis affects the distribution of values for CAm/CCr, impaired tubular reclamation of amylase is the mechanism of the increase in CAm/CCr, and a factor or factors associated with both pancreatitis and with alcoholism per se appear to disorder the renal tubule and to impair tubular reclamation of some but not all low molecular weight proteins-a novel finding of considerable potential significance.