The ovicidal and larvicidal efficacy of essential oils extracted from the tubers of Cyperus giganteus Vahl and Cyperus rotundus Linn. was studied on eggs and fourth instar larvae of Aedes albopictus (Skuse). The eggs and larvae were exposed to serial concentration of the oils ranging from 5-150 ppm and kept under observation for 24h. Both the oils showed remarkable ovicidal and larvicidal activities indicated by EC50 values of <5 ppm and LC50 and LC90 values of <20 ppm. The results obtained suggest that the essential oils of these Cyperus species can serve as a potential source of natural mosquitocidal agents.