Insecticidal and repellent activity of essential oils of Zingiber officinale and Eucalyptus globulus against Culex theileri Theobald, 1903 as a wide-distributed species of mosquitoes in different parts of world with an important role in transmission of infectious organisms and agent were studied. Essential oils were extracted from fresh parts of plants and different concentrations of 250 μl/ml, 500 μl/ml, 750 μl/ml and 1 (undiluted extract) were prepared for each of essential oils. Insecticidal and repellent activity of essential oils against adult form of Culex theileri Theobald mosquitoes, collected from small pools located near the Zayande-Rood River in the Saman city, Iran, were examined via direct exposure method and Y-tube olfactometer bioassay, respectively. Results of current study, as the first study on insecticidal and repellent activity of mentioned essential oils against Culex theileri Theobald, show considerable values of insecticidal and repellent activity against mosquitoes, concentration of one (undiluted extract) had the highest insecticidal and repellent activity against Culex theileri Theobald for both of essential oils and essential oil of Eucalyptus globulus (66% insecticidal and 74% repellent activity) was more potent than Zingiber officinale (45% insecticidal and 61% repellent activity). This study shows that these essential oils can be considered as good replaces for chemical pesticides but more experiments are need for this purpose. Study on insecticidal activity of these essential oils in the field condition can be considered as a subject for next experiments.