Culex pipiens in Egypt is widely distributed and is the main vector of lymphatic filariasis, West Nile virus, and Rift Valley fever. The Present study was laboratory conducted to evaluate the larvicidal effects of some local materials: petroleum oils (odourless kerosene, kerosene, solar, lubrication cut of petroleum oil and motor oil), emulsifiable oils such as CAPL2 (Central Agricultural Pesticides Laboratory) and commercial petroleum oil, tar oil, and surfactant such as Sisi6 against the mosquito, Culex pipiens larvae under two different conditions; at winter (18 ± 2 °C) and summer (38 ± 2 °C). The obtained results indicated that odourless kerosene, kerosene, surfactant  (Sisi6) and the commercial petroleum oil (Zed-oil) were considered successful larvicides under both temperatures since they gave mortality percentage of >90% after 24 hours exposure, while solar and CAPL2 succeeded only under summer temperature but lubrication cut of petroleum oil, motor oil, and tar oil didn't succeed under both temperatures. Also, the study indicated that there is an inverse correlation of viscosity of any petroleum oil and its larvicidal effect. Moreover, toxicity was indirectly related to material viscosity.  As a conclusion, for controlling larvae under any condition, it is recommended that the petroleum oil should have a viscosity of =< 12 milli-poises.