Poly(3,3,3-trifluoropropylsilsesquioxane) (Prf-T) and poly(3,3,4,4,5,5,6,6,6-nonafluorohexylsilsesquioxane) (Hxf-T) were synthesized via the hydrolysis of trichloro-3,3,3-trifluoropropylsilane and trichloro-3,3,4,4,5,5,6,6,6-nonafluorohexylsilane, respectively. The related resin-like fluorosilicone polymers containing dimethylsiloxy units were also prepared. Contact angle measurements were carried out after the polymers were crosslinked by condensation. The solid surface tensions were determined from the combined Owens-Wendt/Young equation using water and methylene diiodide contact angles. The value obtained for Prf-T resin (20 mN/m) is similar to the value for poly(methylsi1sesquioxane) as the unfluorinated silsesquioxane analogue (21,5 mN/m). On the other hand, the Hxf-T polymer shows a very low surface tension, 7 mN/m, lower than that of the corresponding polysiloxane with linear structure, poly[methyl-(3,3,4,4,5,5,6,6,6-nonafluorohexyl)siloxane]. The surface tensions based on other approaches, such as the Girifalco-Good-Fowkes-Young equation and the Zisman critical surface tension of wetting, were also determined. 0 1993, Huthig & Wepf Verlag, Base1CCC 0025-1 16X/93/$05.00