germastannylation of bis(allenes) with germylstannanes, catalyzed by palladium complexes, for the construction of cis or trans five-membered cyclic systems has been investigated. We observed that the relative stereochemical arrangements of the reaction products depends on the substituents in the reagents containing Ge−Sn σ-bonds. When the reagent Ph3GeSnBu3 was employed in the Pd0-catalyzed carbocyclization of bis(allenes)