•The growth conditions to produce a ZnWO4:Sm single crystals were determined.•The Sm3+ segregation coefficient in the ZnWO4 single crystal was estimated to be 0.023.•The effect of Sm3 + segregation on the ZnWO4 crystal lattice parameters has been investigated.•ZnWO4:148,149Sm crystals were obtained following the established growth technique. The growth conditions to produce a high quality ZnWO4:Sm single crystals by the Czochralski method were determined in this work. The role of the Sm impurity in the formation of bubbles in a ZnWO4 single crystal is discussed. The Sm3+ ions segregation coefficient in the ZnWO4 single crystal was estimated to be 0.023. The effect of non-isomorphic substitution of Sm3 + for Zn2 + ions on the ZnWO4 crystal lattice parameters has been investigated. The X-ray luminescence spectra of ZnWO4:Sm3+ crystals are discussed. Two ZnWO4 crystals doped with samarium enriched in 148Sm and 149Sm isotopes were obtained following the established growth technique, which demonstrates its feasibility and reliability for production of detector for rare nuclear processes studies.