The reaction of [Pt(PCy3)(2)] and GaCl3 resulted in quantitative formation of the adduct [(Cy3P)(2)Pt-GaCl3], the first known platinum gallane complex. Although similar reactivity with GaBr3 and Gal(3) was expected, NMR spectroscopic data revealed a different reaction course. Crystal structure determination proved that, in the latter case, the product of the oxidative addition was formed. The resulting platinum gallyl complexes represent the first example of an oxidative addition of gallium(III) halides to low-valent transition metals.