The effect of NeemAzal (TRIFOLIO-M GmbH, Lahnau), a neem seed kernel extract, on larvae of Aedes aegypti was tested. Second, third and fourth instar larvae were reared in water containing different concentrations of NeemAzal. Mortality rates and the stage in which mortality occurred were recorded. The surviving larvae were left in the treated water until adult emergence and the number of eggs laid by the emerged females was recorded in order to evaluate possible fecundity-reducing effect of sublethal doses of NeemAzal. Continuous exposure to treated water induced molting-inhibition and mortality in all larval instars tested. Sensitivity towards NeemAzal decreased with increasing age of the larvae. For female Ae. aegypti a tendency was observed to lay fewer eggs with increasing NeemAzahl concentration to which they had been exposed during larval development.