Small bowel mucosal biopsy specimens were studied in 52 consecutive patients. Twenty-six patients underwent biopsy by a suction capsule and 16 patients by endoscopy using an 8-mm forceps. Additionally, 10 patients were asked to undergo biopsy by both techniques in the same morning. Material was obtained in 81% of attempts by suction and 100% by endoscopy. Tissue obtained was excellent in 58%, good in 28%, and poor in 14% of suction biopsy specimens. Corresponding grades for endoscopy were 65%, 31%, and 4%. The frequency of abnormal findings was not different by either technique. In the 10 patients who had both procedures, mean time to completion was 43 min by suction and 12 min by endoscopy. Intravenous premedication was used in endoscopy, and patient comfort was judged as excellent in 60% with endoscopy, whereas 60% judged suction biopsy as very uncomfortable. The mean fluoroscopy time of 3.9 min necessary for suction biopsy was eliminated with endoscopy. Biopsy with an 8-mm forceps through the endoscope is the preferred way to obtain tissue from the proximal small bowel.