Abstract: The solid solution of In2Fe2−x Ga x CuO7 (space group P63/mmc) was synthesized and investigated through X-ray diffraction and magnetic susceptibility studies. Limited changes to the lattice parameters were observed as a result of the similar ionic radii for Fe3+ and Ga3+ in the trigonal bipyramidal (TBP) crystallographic site. An increase in the Weiss temperature, along with spin glass behavior are observed from x=0 to x=2, but irregularities in the trend are apparent for x=0.75 and 1. With the highest concentration in magnetic ions, In2Fe2CuO7 appears to have competing nearest neighbor interactions that produce a suppression of the Curie tail and the experimental magnetic moment. In comparison to InFe1−x Ga x CuO4, both solid solutions show an invariable progression of the lattice parameters, but the magnetic properties are greatly affected by the distinct TBP layering schemes. [Copyright &y& Elsevier]