The purpose of this study was to test intraorally the effect of a cobalt-chromium cast reinforcement embedded in the denture base of a maxillary complete denture on the distribution of stress. Eight subjects were selected randomly, and three designs of a cobalt-chromium alloy bar were embedded in the dentures. A strain gauge was attached at three positions around the midline of the polished surface of each denture. Strain in the reinforced dentures was significantly less than strain in dentures without reinforcement. These observations suggest that a cast cobalt-chromium reinforcement reduces strain and could contribute to fracture avoidance deformation in maxillary complete dentures.