Introduction Transthyretin amyloidosis (ATTR) is a rare cause of restrictive cardiomyopathy and/or peripheral polyneuropathy, of a progressive, irreversible and fatal nature, underdiagnosed and with its definitive diagnosis performed late. Early diagnosis, characterization of the type of amyloidosis and subsequent establishment of specific therapy are fundamental for a better prognosis of this disease. We present a case of ATTR where clinical suspicion associated with multimodality diagnosis — nuclear medicine — was able to safely deliver diagnosis, without the need for biopsy. […]