In 2436 duodenoscopies performed in 1979-1980, 142 cases of duodenal erosions were found. In 68% of the cases erosions were autonomous, while in the remaining 32% they were associated with peptic ulcer. Either autonomous or associated erosions were mainly present in males with prevalence of the 4th, 5th and 6th decades of life. Moreover, autumn and spring were the most common times of appearance. With respect to symptomatology, 125 cases complained of dyspepsia with a prevalence of ulcer-like symptoms in both autonomous and associated erosions: in the remaining 17 patients hematemesis and melena were the main symptoms. The intake of alcohol and of coffee, as well as the smoking habit did not reveal any particular pattern in these cases, while the association with recent consumption of potentially mucolytic drugs was frequent. In addition, the last 38 cases of autonomous duodenal erosions were studied from the anatomo-functional point of view, revealing the presence of normochlorhydria in 42%, hyperchlorhydria in 47% and hypochlorhydria in 11%: in contrast, fasting gastrinemia was always within normal limits. The histological evaluation of the fundic mucosa showed normal patterns in 71% of the cases, superficial gastritis in 18%, and preatrophic gastritis in 11%. The parietal index was normal in 42% of the cases, high in 47% and low in 11%. The results would seem to suggest that duodenal erosions should be included in the wide spectrum of peptic pathology.