The compounds Ce 2 Fe 17−x Mn x (x=0–3) were synthesized and their structure and magnetic properties were studied. The compounds crystallize in the rhombohedral Th 2 Zn 17 -type structure. Neutron diffraction study of Ce 2 Fe 17−x Mn x solid solutions shows that Mn prefers the 6c site and avoids completely the 9d site, whereas the 18f and 18h sites are occupied almost randomly. The compositional dependences of the unit cell parameters at 293 K are non-monotonous. The binary compound Ce 2 Fe 17 shows ferromagnetic behavior below Θ=94 K and helicoidal antiferromagnetic structure with T N =206 K. The Néel temperature of the compounds Ce 2 Fe 17−x Mn x decreases almost monotonously with increasing Mn content, whereas Θ(x) dependence is non-monotonous. Ferromagnetic order disappears in the range x=0.5–1. Probably, the compounds with 1<x≤2 at low temperatures are inhomogenous ferromagnets consisting of microscopical regions with ferromagnetic ordering. Simultaneously, a short-range helicoidal antiferromagnetic state exists in the latter compounds. A magnetic phase (x−T) diagram is presented. The magnetization curves of the compounds with x=0.5–1 show a metamagnetic transition at ∼(4–7) kOe.