Downstream processing of lipase involving reverse micellar extraction of lipase using cationic surfactant cetyltrimethylammonium bromide (CTAB) was investigated. Effect of various process parameters on both forward and backward extraction of lipase from crude extract was studied to optimize its yield and purity. Complex interaction of salt concentration (0.05~0.15M), surfactant concentration (0.10~0.30 M), and pH (6.0~9.0) for forward extraction, as well as, salt concentration (0.5~1.5 M) and pH (6.0~9.0) for backward extraction have been studied using response surface methodology. Optimum processing conditions, namely, salt concentration 0.16M, surfactant concentration 0.20 M, and pH 9.0 for forward extraction, as well as, salt concentration 0.80 M and pH 7.23 for backward extraction, fulfill the conditions to obtain activity recovery of lipase ${geq}$78% and purification factor of lipase ${geq}$4.0. The study demonstrated that response surface methodology can be used for optimization of the conditions for reverse micellar extraction of lipase.