[en] The compound NpFe₄Al₈ was prepared by direct arc melting of the constituent elements, followed by annealing. It crystallizes in the ThMn₁₂-type structure (space group I4/mmm, a = 8.7480(5) A, c = 5.0372(4) A), with the iron atoms completely and only occupying the 8f positions. Magnetization measurements (T = 2-300 K, B = 0-7 T) show a ferromagnetic-type transition at T_C = 135(2) K and a second anomaly at 118(3) K. The low temperature magnetization cycle is characterized by a hysteresis with a step similar to that previously observed for UFe₄Al₈ single crystals. First-principles density functional theory calculations of the NpFe₄Al₈ band structure point to a magnetic structure similar to that of UFe₄Al₈, in agreement with the observed magnetization cycle. The calculations indicate that the neptunium moment is aligned along one of the a or b axes, and the iron moments form a noncollinear structure in the a-b plane, with the antiferromagnetic and ferromagnetic contributions perpendicular and antiparallel to the neptunium spin moment, respectively