The interfacial microstructure of {001} twist interphase boundaries in AuAg and AuPd bicrystal thin film couples has been investigated by transmission electron microscopy. The bicrystal thin film couples were produced by a new technique described herein. Examination of the bicrystal films showed that orthogonal grids of interphase boundary dislocations of 〈110〉 type formed in the {001} low-angle twist interphase boundaries of both AuAg and AuPd systems. The interfacial dislocations of AuAg interphase boundaries are similar to those of AuAu, i.e., almost screw in character. In AuPd interphase boundaries, the interfacial dislocations show the mixed edge and screw character as expected. The high-angle {001} twist interphase boundaries of AuAg and AuPd were also studied. The concidence lattice concept was applied to study the high-angle twist interphase boundaries. Several critical angles were obtained for both AuAg and AuPd systems. Orthogonal grids of secondary dislocations were observed in the {001} twist interphase boundary of AuAg thin film couples with the twist angle near 36.9°, the critical angle corresponding to the coincidence of ∑ = 5. Experimental evidence of the interfacial dislocation structure of the high-angle twist interphase boundaries of AuPd has not yet been obtained. However, diffraction patterns do show the coincidence character in agreement with what was predicted.