Room-temperature Fe-57 Mossbauer spectra have been measured in Sm2Fe17 under different heat treatment conditions. The details of fitting these spectra is exhaustively discussed. The spectra of Sm2Fe17 are split into seven inequivalent magnetic sites. An identical result was obtained by using two fitting modes. The following has been indicated from the results for all samples. Firstly for these samples containing alpha-Fe sextets and paramagnetic doublets, by choosing an appropriate annealing system, the smallest amount of impurities might be obtained, i.e. an approximately single-phase Sm2Fe17 compound was obtained. Secondly the overall weighted average fields were all approximately equal. This was thought to arise because the different heat treatment conditions caused no change in the near-neighbour coordination of iron atoms. Thirdly the 6c site and 18h site had the largest and the smallest hyperfine fields, respectively.