The synthesis of a dimeric derivative of Gd-AAZTA is reported. It retains the basic properties of the parent complex (q=2, high stability) and displays a relaxivity of 14.0mM−1s−1 at 20MHz and 298K. The outstanding relaxivity is the result of the increased molecular reorientational time and of the contribution arising from 4 to 5 water molecules in the second coordination sphere of the Gd(III) ions.