Results are presented for lattice-parameter and magnetic-susceptibility measurements on a series of solid solutions $\mathrm{Sm}{\mathrm{Sb}}_{x}{\mathrm{S}}_{1\ensuremath{-}x}$. Low-temperature magnetic-susceptibility measurements indicate an inhomogeneous mixed valence for alloys containing low antimony concentrations and a homogeneous intermediate valence at larger concentrations. The susceptibilities of antimony-rich samples illustrate the disappearance of the antiferromagnetic ordering observed in pure SmSb. The alloys of intermediate composition display a nonmagnetic ground state associated with intermediate valence of the samarium cations. The effect of slight sulfur substitution in SmSb on crystalline electric fields is also discussed.