The R3Ni8Sn4 compounds (R = Y, Nd, Sm, Gd, and Tb) have been synthesized and studied by powder X-ray diffraction, magnetic and electrical properties measurements. They crystallize in Lu3Co7.77Sn4 structure type (space group P63mc), and are characterized by different occupancy of some atomic positions, giving 3:8:4 stoichiometry in one case or statistical mixture of Ni and Sn in the other. The magnetic properties were studied in the temperature range 2–300 K and showed that at low temperatures Gd3Ni8Sn4 and Tb3Ni8Sn4 compounds exhibit ferromagnetic and antiferromagnetic ordering, respectively, while at higher temperatures both stannides are Curie-Weiss paramagnets. The Y3Ni8Sn4 stannide is a Pauli paramagnet while in Sm3Ni8Sn4 the magnetism is weak in the temperature range 2–300 K. The electrical properties of the R3Ni8Sn4 compounds showed metallic type of conductivity. The performed electronic structure calculations of Y3Ni8Sn4 are in a good agreement with electrical and magnetic studies.