There is much controversy regarding the chronic nonspecific duodenitis as autonomous clinical entity. We have studied 36 patients (16 women, 20 men), aged 24-59 years (mean age 37.8 years), with biliary dyspepsia and endoscopic changes suggesting "duodenitis"; in all patients the following investigations were carried out: gastric secretion, barium X-ray and histological examination of the duodenal mucosa specimens obtained by endoscopic biopsy. There was no significant difference between the patients with duodenitis and normal subjects regarding the maximal acid output. Unspecific radiological changes were noticed in 55.5% of patients with chronic duodenitis. Endoscopy showed varied changes of duodenal mucosa including edema, erythema, erosions and hypertrophic folds. Histology confirmed the presence of inflammation. The patients have been followed-up for three years and none of them developed duodenal ulcer. We conclude that chronic nonspecific duodenitis is an autonomous clinical entity.