A case of primary amyloidosis located in the larynx in which Beta-2-microglobulin (beta 2m) was the main component of the tissue is presented. Indirect immunofluorescence performed with monoclonal anti-human beta 2 m antibody (BBM1) showed a positive reaction, as did Congo red stain, and both patterns were similar. A significant increase in serum beta 2 m was observed; however, the clinical condition associated with this elevation remains unclear. We suggest that beta 2m is not only the main component of secondary amyloidosis in terminal nephropathy patients undergoing hemodialysis for prolonged periods, but that it could be part of the structure of other types of amyloid--either primary or secondary.