Using data from published clinical trials of acid inhibitory drugs it can be shown that a linear relationship exists between the rate of ulcer healing and the degree of acid inhibition. Since the data used to demonstrate this relationship are group averages of acid reduction and of healing rate, and since there are known to be great individual variations in sensitivity to acid inhibitory drugs as well as in healing rate, it seems likely that the individual relationship between pharmacologic acid inhibition and increase in rate of ulcer healing is different from that which comes out of meta-analysis. Future identification of individual healing curves may form basis for individualized medical treatment in duodenal ulcer diseases.