Reaction of . NO with W(phen)(CO)(2)(SPh)(2) (phen = 1,10-phenanthroline) results in clean conversion to W(phen)(CO)(2)(NO)(SPh). Reduction of the W(II) bisthiolates to the W(0) nitrosyl thiolate occurs with simultaneous reductive elimination of PhS-NO, which is unstable but could be defected spectroscopically. Reaction of W(phen)(CO)(2)(1,2-S-2-Arene), however, does not result in reductive elimination of either free or bound nitrosothiol. Carbon monoxide is displaced, forming W(phen)(NO)(2)(1,2-S-2-Arene) (1,2-S-2-Arene = 1,2-benzene dithiolate or toluene-3,4-dithiolate). Complexes of butanethiol and thiophenol W(phen)(CO)(3)(RSH) react with excess . NO tit form nitrosyl thiolate complexes W(phen)(CO)(2)(NO)(SR). These reactions also produce N2O and HNO2, which are attributed to decomposition of initially formed HNO. These observations indicate that . NO may be capable of direct attack on complexed thiols. Crystal structures of W(phen)(CO)(2)(NO)(SPh) and W(phen)(NO)(2)(toluene-3,3-dithiolate) are reported.