The effect of antacid suspensions and supplementary anticholinergic treatment has been tested by the intragastric pH method in 14 cases of peptic ulcer disease. Common antacids do not usually influence the intragastric pH for more than 5-10 minutes in states of hypersecretion. Antacid suspensions tend to give a more prolonged effect on pH. The combined action of antacid suspensions and anticholinergic substances has been carefully studied in strictly controlled experiments. When these patients were treated basically with anticholinergic drugs even small amounts of antacid suspensions caused a satisfactory and prolonged increase of intragastric pH.