Reaction of R3SnCH2CH(3,5-Me2Pz)2 (R = n-Bu, CH2Ph or Ph; Pz = pyrazol-1-yl) with W(CO)5THF in refluxing THF resulted in the oxidative addition of the inactive R3Sn–C bond to the tungsten atom to yield metal-metal bonded complexes CH2CH(3,5-Me2Pz)2W(CO)3SnR3. While reaction of R3SnCH2CH(mim)2 (R = n-Bu or Ph; mim = 1-methylimidazol-2-yl) with W(CO)6 in refluxing dioxane gave only the decarbonylation complexes R3SnCH2CH(mim)2W(CO)4, no analogous oxidative addition of the R3Sn–C bond was observed. In addition, the reactivity of R3SnCH2CH(py)2 (R = n-Bu or Ph; py = 2-pyridinyl) toward W(CO)5THF markedly depended on the substituent R. The decarbonylation complex (n-Bu)3SnCH2CH(py)2W(CO)4 was obtained when R represented the n-butyl group, and the oxidative addition reaction of the inactive Ph3Sn–C bond took place to give CH2CH(py)2W(CO)3SnPh3 when R was the phenyl group. It is interesting that treatment of (n-Bu)3SnCH2CH(py)2W(CO)4 with I2 led to the unusual reactivity of the (n-Bu)3Sn–C bond to afford complex CH2CH(py)2W(CO)3I with the loss of the organotin group. All these newly synthesized compounds were characterized by IR, NMR and elemental analysis, and their structures were unambiguously confirmed by X-ray crystallography.