Solid lipid nanoparticles (SLN) loaded by Ziziphora clinopodioides Lam. were synthesized using the method of high shear homogenization and ultra sound. The lipid phase consisted of percirol ATO5 and campritol 888 (5% w/v). Poloxamer 188 (2.5% w/v) was used as surfactant. Different amount of essential oil (1, 2, 2.5% w/v) were added to SLN. Particle size of solid lipid nanoparticle loaded by essential oil (2.5%) (SLN-EO) was 241.1 nm with poly dispersity index (PDI) of 0.312 and Zeta potential – 22.6 mv. Entrapment efficiency of SLN-EO (2.5%) was 93%. Transmission electron microscopy (TEM) study showed the spherical particles with the size under 100 nm. Based on the results of fumigant toxicity, the LC50 values of SLN-EO and pure oil against Tribolium castaneum were 30.602 and 68.303 µL. L air−1, respectively. These results demonstrated that SLN-EO had higher toxicity effects on red flour beetles. The comparative assessment of persistence indicated SLN-EO formulation remained effective until 14 days, while the pure oil lost its toxicity after the 8th day of application. Chemical composition of Ziziphoraclinopodioides showed that pulegone (51.78%), 1, 8- cineole (8.95%), p- menthone (7.74%) and piperitenone (5.7%) were the major components.