The study deals with the EO-NP's encapsulated cardamom essential oil for insecticidal activity. The prepared nanoparticles were subjected to characterization studies using Dynamic Light Scattering (DLS) analysis, Fourier Transform Infra-Red spectroscopy (FTIR) and Transmission Electron Microscopy (TEM) analysis. The DLS analysis revealed that the size of the nanoparticles had a slight increase in diameter after three months of storage. Similarly, the characterization with TEM showed that the prepared nanoparticles were of round or spherical shape with clear morphology without any crack in the external surface. Considerable mortality was observed from the insecticidal bioassay carried out by contact, fumigant toxicity with cardamom essential oil nanoparticles encapsulated with PEG (EO-NPs) against adult Oryzaephilus surinamensis (Linnaeus) (Coleoptra: Silvanidae). Further the Cardamom EO-NP's also produced significant repellency effect on the adult insects. About 85% mortality (Contact Toxicity) and 81% mortality (Fumigant Toxicity) was observed with 0.025 mg x cm2 concentration of EO-NP's. The results indicate that the cardamom essential oil encapsulated with PEG nanoparticles could be an effective alternative to chemical pesticides for the control of stored product grain pests. Further this is the first report on the insecticidal efficacy of PEG encapsulated Cardamom essential oil against Oryzaephilus surinamensis.