The co‐assembly between a polyisoprene‐block‐poly(dimethylaminoethyl methacrylate) block copolymer and poly(ureamethylvinyl)silazane is investigated. The hybrid morphology can be controlled by systematically increasing the inorganic‐to‐organic ratio or by changing the molecular weight of the block copolymer. Temperature treatment up to 1 500 °C of the hybrids resulted in mesoporous, ordered non‐oxide‐type ceramics. The results suggest that careful control of co‐assembly processes enables access to nanostructured high‐temperature ceramics that may have novel mechanical, thermal, and chemical properties.magnified image