The main objective of the present work is to construct a simple steam distillation system for extracting volatile oil from peppermint plant. The constructed extraction system consists of the following main parts: electric heater, boiler, extracting unit, condenser and connection hoses. Experiments were carried out to study the effect of boiler inlet water flow rates (1.00, 1.25 and 1.50 l/h) and batch size of whole peppermint plant (300, 500 and 700 g) on system productivity, extraction efficiency, essential oil yield, power and energy requirements. Results indicated that the constructed extraction system using steam distillation technique gave the optimum conditions of system productivity (6.2 ml), extraction efficiency (88.57 %), essential oil yield (0.797 % (w/w)) and energy requirements (0.475 kW.h/ml) under 1.5 l/h boiler inlet water flow rate and 700 g batch size.