The mixed fluoride series Fe 1− x Cr x F 3 (0 ⩽ x ⩽ 1), synthesized by solid state reaction, crystallizes in space group R 3 c, identical to that of r-FeF 3 and r-CrF 3. Mössbauer spectroscopy gives clear evidence for six-fold coordinated trivalent high-spin iron ions and magnetic susceptibility for antiferromagnetic interactions. Both Mössbauer and susceptibility measurements have clearly revealed reentrance phenomena and magnetic spin-cluster structures; these properties which result from the presence of short-range spin correlations, are strongly dependent on the chromium content and on the synthesis conditions. By accounting for magnetic studies previously discussed on the Fe 1− x Ga x F 3 series, we can confirm the paramagnetic Curie temperature value θ p of r-FeF 3 from the literature. In addition, one can conclude in favour of nonnegligible antiferromagnetic interactions between second next nearest neighbours: such a phenomenon agrees well with the presence of magnetic frustration in these compounds, experimentally observed through the values of | θ p/ T N |.