Experience is recorded with 893 operations of duodenal ulcer for a period of 15 years. Of these, 872 patients (97.6 per cent) were operated as nonemergency planned cases, 48 of them subjected during a period of 7 years to proximal selective vagotomy in 3 variants. During the postoperative period one patient died of fatty pulmonary embolism. During the early postoperative period in 4 patients developed bronchopneumonia (8.3 per cent), in 3 transient cardiospasm (6.2 per cent) successfully controlled without surgical intervention. According to Visick's classification, excellent and very good postoperative results were recorded in 41 patients (87.2 per cent). Recurrent ulcer was demonstrated in 3 patients (6.4 per cent); only one of them required operative treatment--antrumectomy with revagotomy. It is pointed out that postoperative pH-metry of the stomach is not a pathognomonic sign, but may be criterion for a potentially possible recurrence. Continuous control is needed, since the majority of recurrent ulcers are not manifested by characteristic clinical symptoms.