A case of histologically proven dilated cardiomyopathy and a case of clinically diagnosed cardiomyopathy (cardiac amyloidosis was strongly suspected but was not confirmed) were examined with 99mTc(V)-dimercaptosuccinic acid (DMSA). 99mTc(V)-DMSA accumulation in the damaged myocardium was clearly demonstrated. These results suggested the possibility that 99mTc(V)-DMSA could be used as a positive agent for cardiomyopathy.