A histologic study was carried out on tissues from 87 patients who had undergone surgical decompression of the median nerve to determine the incidence and relationship of amyloid deposition to the carpal tunnel syndrome. Using histochemical and electron microscopic technics, amyloid was found in tissues from two male patients with the apparent idiopathic form of the disease. These data are significant, in that they show that screening of tissues from such patients is of value. This study is the first to demonstrate the submicroscopic pattern of amyloid deposits associated with the carpal tunnel syndrome. The focal deposits of the fibrils show pericollagenous distribution with separation of the individual collagen fibers, a morphologic pattern which contradicts recent reports based on light microscopy.