The load capacity of complete upper dentures objectively proved greater than that of lower dentures. 2. The load capacity and, consequently, the stability of position of the lateral area of upper dentures objectively diminished with advancing time of wearing, but increased in the lower jaw. 3. The stability of complete dentures is not determined exclusively by the quality of the denture bearing tissue. 4. The measured stability of position of complete dentures did not correspond with the subjective impression of full function; in general, this was stated to be as good as ever by all patients.