The diarylmercurials, R2Hg [R = Ph, p-XC6H4 (X = Me, Br, Cl, or F), 2, 3, 4-Cl3C6H2, 2, 4, 5-Cl3C6H2, 2-naphthyl, or 8-quinolyl], have been prepared in satisfactory yield by sulphur dioxide elimination reactions on heating the corresponding mercuric arenesulphinates under vacuum, but decomposition of mercuric p-acetamidobenzenesulphinate gave acetanilide. The mercuric arenesulphinates were obtained by reaction of mercuric acetate with the appropriate sodium arenesulphinates in aqueous solution at room temperature. Similar reactions in boiling aqueous solution gave either diarylmercurials, R2Hg [R = Ph, p-XC6H4 (X = Me, F, or MeCONH), 2, 4, 6-Me3C6H2, 2, 4, 6-(Me2CH)3C6H2, or 8-quinolyl], or arylmercuric arenesulphinates, RHg(02SR) [R = p-XC6H4 (X = Br or Cl), 2, 3, 4-Cl3C6H2, 2, 4, 5-Cl3C6H2, or 2-naphthyl], usually in low yield, and sulphur dioxide. Mercury-carbon bond formation also occurred in reactions of mercuric acetate with sodium mesitylenesulphinate and 2, 4, 6-triisopropylbenzenesulphinate at room temperature, mesitylmercuric mesitylenesulphinate and bis(2, 4, 6-triisopropylphenyl)mercury, respectively, being obtained. The sulphur-oxygen stretching frequencies of the mercuric arenesulphinates are indicative of S-sulphinate coordination, whilst those of the arylmercuric arenesulphinates are consistent with unidentate O-sulphinate groups.