Reaction of ruthenium bis-acetylide complexes with 2,6-lutidinium tetrafluoroborate gave butenynyl complexes cis-[Ru(eta(3)-RC CC=C(H)R)(PMe(3))(4)]BF(4) in moderate to good yields. The structure of cis[Ru(eta(3)-tBuC CC=C(H)tBu)(PMe(3))(4)]BF(4) was determined crystallographically. Attempts to prepare cis[Ru(eta(3)-MeC CC=C(H)Me)(PMe(3))(4)]BF(4) resulted in the formation of two isomers, which differ in the stereochemistry about the double bond. The reaction of two bis-acetylide complexes with methyl triflate afforded butenynyl-type complexes cis- [Ru(eta(3)-RC CC=C(Me)R)(PMe(3))(4)](+) (R = Me, Ph). The mixed acetylide-vinylidene complex trans-[Ru(C CSiMe(3))(C=CH(2))(PMe(3))(4)]PF(6) was prepared by the reaction of trans-Ru(C CSiMe(3))(2)(PMe(3))(4) with ammonium hexafluorophosphate. In addition, the crystal structure of trans-[Ru(C CH)(C=CH(2))(PMe(3))(4)]BF(4) is reported.