A computational and experimental study of the deformation and breakup properties of nonturbulent round liquid jets in uniform gaseous cross flows is described, seeking to develop numerical predictions to find these properties at conditions that are difficult to address using experiments. The time-dependent incompressible two-dimensional Navier-Stokes equations were solved in the gas and liquid phases in Conjunction with the level-set method to determine the position of the liquid-gas interface of the deforming liquid jets. The computations were evaluated satisfactorily based on earlier measurements of the properties of solid circular cylinders in cross flow (recirculating wake lengths, drag coefficients, conditions for the onset of eddy shedding, and frequencies of eddy shedding) and the present measurements of the properties of nonturbulent round liquid jets in cross flow (liquid jet cross-stream deformation, liquid jet streamwise deformation and deflection, and breakup regime transitions). Subsequent computations to find liquid jet deformation and breakup properties revealed relatively small effects of liquid-gas density and viscosity ratios on deformation and breakup regime boundaries. Small cross-flow Reynolds number conditions approaching the Stokes flow regime, however, resulted in a significant increase of the resistance of liquid jets in cross flow to deformation that has not been addressed by existing measurements of breakup properties.