The present invention relates to stabilised 99mTc radiopharmaceutical compositions of the ligand tetrofosmin, which include an ascorbic acid or ascorbate radioprotectant, in the absence of an antimicrobial preservative. The invention also provides lyophilised kits suitable for the bulk preparation of multiple unit patient doses of 99mTc-tetrofosmin metal complexes. Also disclosed are unit doses of 99mTc-tetrofosmin, together with processes for preparing such unit doses from the lyophilised bulk vial.