Abstract: Background and Objective: Insecticides are widely used to protect grains during stored against many insects, it caused serious adverse effects on grains, seeds, birds, humans and increase water, soil and environmental pollution. Therefore, nanotechnology including nanoformulations and green insecticides are interesting for control storage and planting grains insects. The current study was carried out for the first time to formulate nanoemulsion of camphor essential oil (EO) by ultrasonic and assess its insecticidal activity on wheat weevil, Sitophilus granarius. Acute and sub-chronic toxicity also were studied on male albino rats. Methodology: Camphor (Eucalyptus globulus) was obtained from leaves by hydrodistillation and analysis by GC/MS. Nanoemulsion of EO was formulated by ultrasonic and characterization. In addition, insecticidal activity and toxicological studies were investigated and statistical analysis by the log-probit software program Ldp Line® and SPSS version 18.0 for windows, respectively. Results: The EO to surfactant ratio was correlated to nanoemulsion droplet size and stability. Stable camphor EO formulation having a droplet of 99.0 nm was formulated after 40 min of sonication. Camphor nanoemulsion showed high insecticidal activity against wheat weevil, Sitophilus granarius with LC50 181.49 μg g–1 compared to 282.01 μg g–1 of EO. The activity of EO could be due to the presence of 1,8-Cineole, β-cymene, D-limonene, α-pinene and α-terpineol which found in camphor EO by GC-MS analysis. Camphor nanoemulsion did not show any effect on germination or seedling growth. Acute and sub-chronic toxicity studies show no signs of toxicity and no biochemical alteration in liver biomarkers of male rats. Conclusion: These findings show that camphor nanoemulsion development as green and nano insecticide product. This study also concludes that the potential use of camphor EO nanoemulsion to protect grains against Sitophilus granarius and other insects.