AbstractThe subject of the present study is to investigate the deformation and fragmentation of a moving droplet in a zero gravity uniform gas flow. The lattice Boltzmann method is employed to simulate different modes of deformation and breakup of the drop. Two‐dimensional results are compared with axisymmetric computations and major difference in the mechanisms of breakup and the rate of deformations is shown. Influence of the drop and gas viscosities as well as surface tension effect is investigated for some range of the Reynolds and Weber numbers. It is seen that the increase of the Reynolds or Weber number results in the increase of drop deformation and finally breakup. The quality of the findings is similar to the experimental observations. Different breakup regimes such as bag breakup and shear breakup are observed. The primary breakup time and the cross‐stream radius of the axisymmetric drop before bag breakup are shown to be in satisfactory agreement with experimental data. Copyright © 2009 John Wiley & Sons, Ltd.