Preparation, X-ray diffraction and ac susceptibility of Nd0.7Pr0.3Ba2-kSrkCu3O6+z (0 less than or equal to k less than or equal to 1) are reported. An orthorhombic to tetragonal transition was observed for k greater than or equal to 0.75. Superconductivity occurred only for k greater than or equal to 0.25. When the samples were heated in argon prior to oxygen annealing both the orthorhombicity (for 0 less than or equal to k less than or equal to 0.75) and T-c increased (by 10 K for k = 1). Though a weakening of Pr-f hybridization with Cu-O bands due to Sr substitution may explain the data, a detailed knowledge of oxygen defect chemistry will be required to understand the behavior of Pr in LnBa(2)Cu(3)O(6+z) (Ln = rare earths).