T he influence of certain factors that may affect the role of Sphaerodema urinator Dufor as a mosquito predator was investigated. Water depth and surface area showed no marked effect on nymphal duration and mortality as well as longevity, sexual maturation, fecundity, fertility, sex ratio of adults and mosquito consumption. Whereas, water quality, water surface flora, temperature, photoperiod and light intensity had marked effects on the aforementioned parameters. It seems that clear, unpolluted, duckweed free water, long day photoperiod (16L: 8D), low light intensity (681.8 Lux) and moderate temperature (25 – 30 ˚C) are more suitable for the breeding of this promising biocontrol agent of mosquitoes.