Thin-walled (wall thickness, 100-2000 mum) mono- and bilayered ceramic tubes in the system Si-O-C-(N) were obtained by centrifugal casting of a polysiloxane/filler suspension. Si and SiC powders were dispersed in polyorganosiloxane/triethoxysilane solutions. After centrifugal casting in a Teflon tube with a rotational speed of 2000 rpm and subsequent cross-linking at 130degreesC and 60 rpm, the tubes were pyrolyzed in argon or in nitrogen at 1400-1600degreesC. Bilayered tubes with controlled variation of porosity were obtained by overcasting the monolayer green tubes with a modified slurry composition.