In as-cast Sm 2 Fe 1 7 the high amount of α-Fe caused by a peritectic reaction can be considerably reduced by a small addition of about 1 at% Zr. X-ray diffraction showed that as-cast Sm 1 0 . 5 Fe 8 8 . 5 Zr 1 . 0 mainly consists of a phase with the Th 2 Zn 1 7 -type structure and SmFe 3 . Non-homogenized Sm 1 0 . 5 Fe 8 8 . 5 Zr 1 . 0 was milled and (i) annealed in vacuum or (ii) treated with a hydrogenation-disproportionation-desorption-recombination (HDDR) process. The annealed and subsequently nitrogenated powder is magnetically anisotropic and has a coercivity μ 0 j H c up to 2.0 T and an energy product (BH) m a x up to 136 kJ/m 3 . HDDR-treated and nitrogenated powder is isotropic and exhibits values of μ 0 j H c = 3.1 T and (BH) m a x = 103 kJ/m 3 . Consequently, Sm 1 0 . 5 Fe 8 8 . 5 Zr 1 . 0 N y (y 16) permanent magnets with very good properties can be prepared without the time-consuming homogenization procedure.