The results are reported from the treatment of 30 patients with gastric and 13 with diodenal ulcers with biogastrone in the course of 20 days (300 mg were given the first week, where on -- 150 mg daily). A more favourable effect upon the clinical symptoms and ulcer were observed in the patients with gastric ulcer (the symptoms disappeared in 87 per cent whereas the ulcer -- in 32 per cent) as compared with the duodenal ulcer (the symptoms disappeared in 46 per cent, whereas -- the ulcer in none). Biogastrone treatment influences the pain in a higher per cent as compared with Caved-S and oxyferroscorbon (p greater then 0.05), whereas regards the rest of the clinical symptoms -- no statistically significant difference was established. As compared with the treatment with oxyferroscorbon, Caved-A and cimetidin, biogastrone has a slower effect on the subjective complaints and the ulcer niche. After biogastrone treatment, the indices of gastric secretion and acidity decrease and the sialic acid in gastric juice is increased only in the gastric ulcer, but does not change considerably in the duodenal ulcer. The rest of the laboratory indices do not change with biogastrone treatment. In two of the patients, in the course of biogastrone treatment, light edema appeared on the face and the arterial blood pressure was elevated in other two, disappearing after the treatment without any additional treatment. Biogastrone treatment is indicated mainly in cases with gastric ulcer, with decreased sialic acid in gastric juice.