Surface strains of a maxillary posterior four-unit fixed partial denture were measured as a function of occlusal loading site and magnitude. A gold alloy and a chromium alloy fixed partial denture with first bicuspids and second molar abutments were used; the former was designed for pin facings and the latter for Steele's facings. The results showed that even a relatively simple fixed partial denture does not function as a simple beam. A gage near the soldered joints showed that, when the loading was near the opposite end of the fixed partial denture, it functioned to a considerable extent as a cantilever with respect to the opposite gage: however, when loading was near the gage, that portion of the fixed partial denture was in simple compression. The gage in the center of the fixed partial denture showed that loading on the ends resulted in cantilever action, while loading in the center resulted in mostly transverse bending. The measurements on the chromium alloy fixed partial denture illustrated that the type of attachment for the facing caused variation in the surface strain and that the high modulus resulted in low strain values compared to the gold alloy fixed partial denture.