Polysilsesquicarbodiimide xerogels have been prepared by sol-gel processing of chlorosilanes, R
(R = H, alkyl or aryl;
= 0, 1, or, 2) and bis(trimethylsilyl)carbodiimide. The reactions can be performed with or without organic solvents and are catalyzed by pyridine. Depending on the solvents and the applied experimental conditions, the product is obtained as a fine powder or as a gel. Heat treatment transforms the xerogels to ceramic materials in the ternary Si/C/N system.