Eucalyptus globulus was assayed for its larvicidal potential against mosquito larvae (Culex pipiens). Efficacy of Eucalyptus extract was examined as an acceptable alternative for chemical control. Both seed extract and leaf extract were screened in laboratory conditions. Applying seed extract and leaf extract at 1000 ppm caused 100 and 80% mortality in larvae of Culex pipiens, respectively. Larvicidal activity of extract of Eucalyptus was dose dependent. This suggested that the seed and leaf extracts contain compounds toxic to mosquito larvae, which can be developed and used in the control of mosquitoes. Further studies of these plants as possible agents for mosquito control are recommended.