A new system to continuously produce class III plant peroxidase enzyme by the immobilized callus cultures of Tecoma Stan var. angustata using a Packed Bed Reactor is described. Batch cultures were used for the partial characterization and optimization of the enzyme. A maximum productivity of 2478 X 10 4 U l–1 h–1 was obtained at a residence time of 15 X 10–3 h using full-strength Murashige and Skoog’s (MS) medium. At optimum conditions of flow rate (0.3 ml min–1), sucrose concentration (20 g l–1), pH (5.0) and temperature (50 °C), the half-life of the enzyme production reached only on the 50th day when fed with half-strength MS medium. Metal ions (1mM concentration) such as Fe2+, Ca2+, Cu2+ and Na+, when provided separately along with the culture medium rapidly increased the enzyme activity on the 50th day of its production.