The results of a non-radioactive, peroral absorption test have been compared with the results of the traditional Schilling test in 31 cobalamin-deficient patients. The non-radioactive test is simple to perform, is less costly than the Schilling test and seems to give reliable results. The non-radioactive test should be performed after cobalamin treatment, but not until the plasma cobalamin value has declined to below 450 pmol/l. Normal Schilling test was noted in one-third of the patients, while normal non-radioactive test was noted in only one-fifth of the patients. The results reveal some discrepancies between the two tests regarding the response to intrinsic factor. In the non-radioactive test without intrinsic factor, the great variation in values may reflect varying secretion of intrinsic factor, possibly secondary to infestation with Helicobacter pylori. "False normal" Schilling test seems to be more common than previously believed.