Insecticidal activities of methanol and water extracts obtained from in vitro propagated of Ceratophyllum demersum L., were tested on adults of the granary weevil Sitophilus granarius L.. In vitro shoot regeneration was achieved from shoot tip explants of C. demersum cultured on liquid Murashige and Skoog (MS) media containing various combinations of 6- Benzylaminopurine (BAP) and 1-Naphthaleneacetic acid (NAA). Mortality percentages of the insects exposed to different concentrations (2.5, 5, 10 and 20 mg/ml) of the extracts at different intervals of 24, 48 and 96 h were determined. Methanol (99%) and water extracts gave (100%) mortality after 96 h. The lowest median lethal concentration (LC50) values of methanol and water extracts after 96 h were: 2.505 and 1.153 mg/ml, respectively. Furthermore, positive correlations at p < 0.01 level between mortality and concentration; mortality and exposure time for both extracts was detected. Based on the present results, it can be concluded that this aquatic plant extracts of C. demersum may have a potential action for control of S. granarius adults and can be suggested against storage pests.