Fumigant toxicity of the essential oil derived from Carum copticum C.B. Clarke (Apiaceae) were assessed against growth stages of Indian meal moth, Plodia interpunctella (Hubner) (Lepidoptera: Pyralidae). Seeds of the plant were collected from Tehran, Iran and hydrodistilled to extract their essential oil. The essential oil was analyzed by GC and GC-MS. Thymol (64.51%), γ-terpinene (17.52%) and p-cymene (16.16%) were the main components among the eight constituents characterized in the oil, representing 98.19% of the total components detected. All bioassay tests were conducted at 25 ± 1°C, 65±5% RH and photoperiod of 16:8 h (light:dark). After preliminary dose-setting experiments, LC50 and LC90 values of four growth stages including eggs, larvae, pupae and adults were calculated. Results showed that the toxicity on the growth stages of Indian meal moth was differed markedly. Adult insects were about 500 times (LC50 = 257.83 μl/m3 air and LC90 = 598.94 μl/m3 air) more susceptible than other growth stages. Moreover, last instar larvae (LC50 = 91.36 μl/l air and LC90 = 213.79 μl/l air) and pupae (LC50 = 105.69 μl/l air and LC90 = 203.24 μl/l air) were significantly more susceptible than eggs (LC50 = 184.61 μl/l air and LC90 = 435.32 μl/l air). These findings indicated that essential oil from seeds of C. copticum could have potential of practical value for application in management of the Indian meal moth in storage.