A study was conducted between 2012 and 2014 on the protective efficacy of diatomaceous earth (DE) formulations against Sitophilus oryzae L., 1763 (Coleoptera: Curculionidae) (rice weevil), a major pest of the stored rice. Biological tests were carried out at 30°C and 75% RH on rice treated with DE formulations. In the biological tests, different concentrations of Protector ® (DE formulation) and DEA-P [mixture of natural DE (83%) and 0.25% abamectin (w:w)] were used. After DE treatment, dead adults were counted once a week for a month and percentage mortalities were determined. In order to determine progeny production (F 1 ) , rice was also incubated under the same conditions for a 60-day period. Protector ® gave 100% mortality to S. oryzae adults at 1000 ppm after 14 d, and DEA-P gave the same mortality rate at 75 ppm at the same time. In studies to determine progeny (F1) emergence, Protector ® resulted in 100% mortality at 1750 ppm after 60 d of storage, while DEA-P caused 100% mortality at 50 ppm concentration. In conclusion, the protective effect of both DE formulations was confirmed, however DEA-P was more effective against S. oryzae at lower concentrations than Protector ® .