Abstract A numerical study on the ignition behavior of one-dimensional monodispersive sprays is conducted. The effects of key parameters are clearly defined. In particular, the existence of the optimum equivalence ratio and its functional dependence on initial droplet size and fuel volatility are established. Similarly, the existence of the optimum droplet size and its functional dependence on equivalence ratio and fuel volatility are studied. The ignition behavior is strongly nonlinear near fuellean and small initial-droplet mixtures. This causes a substantial improvement in ignitabiliry of fuel-lean mixtures for the heterogeneous sprays as compared with the corresponding homogeneous mixtures. The investigation on ignition sources indicates an Arrhenius type of dependence of the ignition delay time on the source temperature. An attempt is made to compare the numerical results with experimental data. The comparison shows a reasonable agreement despite its qualitative nature due to the limited experimental data.