A retrospective study was made of 168 patients who underwent jejunal biopsy during a 2 year period at the Mayo Clinic in an attempt to correlate small-bowel roentgenologic and biopsy findings. The results re-emphasize the fundamental role of the small-bowel biopsy in establishing the diagnosis of sprue. Small-bowel roentgenologic examination reveals false-negative findings in a significant percentage of patients with sprue. However, in conditions such as regional enteritis, neoplasia, and sequelae of gastrointestinal surgery, smallbowel roent-genologic examination can provide valuable and highly specific diagnostic information. Data correlating roentgenologic abnormalities with final clinical diagnoses support the conclusion that-the various roentgenologic signs of malabsorption are nonspecific. Physical changes in barium suspensions are probably the cause of segmentation-flocculation patterns, and a similar mechanism very likely accounts for the apparent thickening of valvulae conniventes in cases in which no histopathologic changes are present in the small bowel.