Abstract.1,1,3,3,5,5-Hexavinyl-1,3,5-trisilacylohexane [Si(CH=CH 2 ) 2 CH 2 ] 3 was synthesized and hydrosilylated with trichlorosilane to afford the first generation of a dendrimer. Conversion of this molecule with 18 Si-Cl functions on its surface with an excess of vinylmagnesium bromide yielded the 18-fold vinylated dendrimer.