A study has been carried out on self-compacting paste (SCP) systems using various cements and secondary raw materials (SRM’s) including rice husk ash (RHA) and Silica Fume (SF). These systems were characterized by SRM particle size, powder water demand (WD) and setting times, flow, strength, microstructure and early volume stability. The results show that WD increased by adding SRM’s due to their smaller particle size, higher surface areas and internal porosity. Inclusion of SRM’s in SCP systems as cement replacements also increases strength of SCP systems due to filler, hydration and pozzolanic actions which translate into pore refinement. It is demonstrated that the resultant properties of self-compacting cementitious systems (SCCS) depend upon the nature of SRM used.