The dairy industry throughout the world is facing the problem of disposal and reutilization of surplus whey. The present work is done to produce a valuable industrial product like lactic acid from the whey with the use of Lactobacillus plantarumMTCC 2621. The effect of various environmental conditions was studied to maximize the lactic acid content. The pH 6.0 and 6.5 and temperature of 37ï°C showed themaximumproduction of lactic acid i.e. 1,40,000 mg/l. 60gm/l D-glucose concentration shows the maximumgrowth of L. plantarumi.e. 1,72,000 cells/m3.The bestworking sample size, inoculum size and the incubation temperature for L. plantarum to produce lactic acidwere found to be 50ml, 10%(v/v) and 48h. The immobilized cells worked best upto 3rd cycle and the results are compared to those of free cells and the values found out to be 8,00,000 mg/l and 1,08,000mg/ l respectively.