Agricultural pests, diamondback moth (Plutella xylostella), green peach aphid (Myzus persicae) and two-spotted spider mite (Teyranychus urticae), are becoming major pests in human dwellings in a variety of ways across the world. For management of these pests, the essential oils of Coriandrum sativum and Cinnamomum cassia prepared by steam distillation, hexane extraction and supercritical extraction methods were evaluated for the insecticidal effects. Using the contact bioassay, the LD50 value of C. sativum oil by steam distillation extraction method was 30.59 μg/cm2 against M. persicae adults. The LD50 values of C. cassia oils prepared by steam distillation and hexane extraction methods were 5.96 and 4.64 μg/cm2, respectively, against T. urticae adults, and LD50 value of the essential oil by supercritical extraction method was 6.50 μg/cm2 against M. persicae adults. This study showed that C. sativum and C. cassia oils could be an effective natural acaricide and insecticide against agricultural pests.