Certain physico-chemical characteristics of mosquito breeding habitats [temperature, pH, salinity, turbidity, dissolved oxygen (DO) and nitrite] were examined relative to the distribution of mosquito larval species in two urban areas of Cairo Governorate namely El-Muqattam (M) and Abu-Seir (A). Mean values and ranges of such characteristics for the reported mosquito species (Culex pipiens, Cx. perexiguus, Ochlerotatus caspius, Cx. pusillus and Culiseta longiareolata) were reported. In conclusion, based on the significant correlations of the different characteristics with the abundance of the two common larval species (Culex pipiens and Cx. perexiguus), salinity and DO may be considered the predictor variables associated with the immature abundance. Considering altogether mosquitoes, there is an increasing presence from planned safe (M) to unplanned unsafe (A) habitats mainly due to turbidity and nitrite.