99mTc-sodium pertechnetate was reduced and complexed with 1,2-dihydroxy-1,2-bis(dihydroxyphosphinyl)ethane (DHPE) with a yield higher than 95%. When administered to rats, 99mTc-DHPE demonstrated very good skeletal uptake, a high clearance from blood to the bones a low concentration in muscles and other organs, satisfactory biological stability and a clearance mainly through the kidneys. The biodistribution of 99mTc-DHPE in rats compared to that of 99mTc-methylenediphosphonate (99mTc-MDP) at 2 and 24 h post injection, showed higher skeletal uptake, substantially higher blood clearance, but also higher concentration in muscles which, however, caused no significant degradation in image quality. These characteristics suggest that 99mTc-DHPE is a promising new skeletal imaging agent.