The capability of calcite precipitation by microbes is a well-known natural phenomenon and is now successfully employed to improve properties of concrete. The calcite precipitation by microbes will be affected by the process in which bacteria is introduced into concrete. The present study highlights different ways ofmicrobial incorporation into concrete and its effect on the properties of resultant concrete. The bacteria were introduced into concrete either during casting or curing of concrete. The efficiency of the proposed microbial treatment was monitored in terms of strength development, water impermeability, pH of the pore solution, microstructure and level of CaCO₃ precipitated. It was observed that both admixed treatment or spray treatment during curing were effective in calcite precipitation. The procedure involving spraying of bacterial culture onto concrete surface was efficient as well as economical.