Essential oil is one of plant metabolism products formed by the reaction of various compounds from a plant. One of essential oils comes from the leaves and peels of kaffir lime. The purpose of this research was to study the water distillation and steam distillation methods to extract the essential oil from kaffir lime leaves and peels with various pre-treatment and without pre-treatment (fresh leaves and peels). Kaffir limes used in this research were obtained from Madiun, East Java. The pre-treatment processes were carried out by drying the materials in the oven (at 60°C for 1 hour and 2 hours) and in the microwave (at 450 W and 300 W for 3 minutes). The distillation process was carried out for 5 hours and its operating conditions were at 100°C and atmospheric pressure. The distillate containing oil and water was separated to obtain the pure essential oil. The essential oil with the highest yield was then analyzed by GC-MS. The results of the study showed that the highest yield of essential oil (1.51%) of kaffir lime leaves was obtained by the steam distillation method through the pre-treatment of dried leaves in the microwave at 450 W for 3 minutes. Meanwhile, the highest yield of the essential oil (0.81%) of kaffir lime peels was obtained by the water distillation method from fresh kaffir lime peels.