The elasto-plastic response of the precursor derived Si-B-C-N ceramics upon contact loading was determined by depth sensing nanoindentation technique. The indentation response of as-thermolyzed Si-B-C-N ceramic was compared with the heat-treated counterpart. The as-thermolyzed ceramic was X-ray amorphous and the heat-treated ceramic was phase separated and crystallized. The hardness and reduced elastic modulus values of the as-thermolyzed ceramic were ~16GPa and ~172GPa, respectively. The reduction in hardness to ~9GPa in the heat-treated ceramic was attributed to phase separation and crystallization of SiC and Si3N4. Furthermore, high elastic recovery with a plastic work ratio of ~0.3 was observed and ascribed to volume controlled deformation mechanism. © 2013 Elsevier Ltd.