( Gd , Y ) 3 ( Fe , Ga ) 5 O ‐ 12 films have been prepared by liquid phase epitaxy on (111) Gd 3 Ga 5 O 12 substrates at deposition temperatures ranging from 760 to 1010°C. The substrate‐film misfit strain, measured at room temperature, has been found to vary monotonically over this range of deposition temperatures from −23×10 −4 to +10×10 −4 , where the positive sign corresponds to the film being in tension. The uniaxial magnetic anisotropy energy of these films has been studied by measuring both the uniaxial anisotropy field and the magnetization as a function of the misfit strain. Large positive values of the uniaxial anisotropy energy have been measured for films in compression, a result which is contrary to that expected for a negative λ111 and a stress induced anisotropy. Possible explanatory mechanisms involving the misfit strain at the deposition temperature are discussed.