The gallium-rich intermetallic phases REPdGa 3 (RE=La, Ce, Pr, Nd, Sm, Eu) were obtained by arc-melting of the elements and subsequent annealing for crystal growth. The samples were studied by X-ray diffraction on powders and single crystals. The structures of three crystals were refined from X-ray diffractometer data: SrPdGa 3 type, Cmcm, a=634.3(1), b=1027.2(1), c=593.5(1) pm, wR=0.0621, 380 F 2 values, 20 variables for CePd 0:80(4) Ga 3:20(4) , a=635.9(1), b=1027.5(1), c=592.0(1) pm, wR=0.1035, 457 F 2 values, 19 variables for CePdGa 3 , and a=640.7(1), b=1038.2(1), c=593.7(1) pm, wR=0.0854, 489 F 2 values, 19 variables for EuPdGa 3 . The REPdGa 3 gallides are orthorhombic superstructure variants of the aristotype ThCr 2 Si 2 . The palladium and gallium atoms build up polyanionic [PdGa 3 ] δ- networks with Pd-Ga and Ga-Ga distances of 248 - 254 and 266 - 297 pm, respectively, in EuPdGa 3 . The rare earth atoms fill cavities within the polyanionic networks. They are coordinated by five palladium and twelve gallium atoms. Taking CePdGa 3 as an illustrative representative, the band structure calculations show largely dispersive itinerant s, p bands and little dispersive d (Pd) and f (Ce) bands, the latter crossing the Fermi level at large magnitude leading to magnetic instability in a spin-degenerate state and a subsequent antiferromagnetic ground state with a small moment of ±0.36 μ B on Ce. The bonding characteristics indicate a prevailing Ce-Ga bonding versus Pd-Ga and Ce-Pd. Temperature-dependent magnetic susceptibility and 151 Eu Mössbauer spectroscopic measurements point to stable trivalent lanthanum, cerium, praseodymium, and neodymium, but divalent europium. SmPdGa 3 shows intermediate valence. Antiferromagnetic ordering occurs at T N =5.1(5), 7.0(5), 6.3(5), 11.9(5), and 23.0(5) for RE=Ce, Pr, Nd, Sm, and Eu, respectively.