This work has two-fold contributions. First, a detailed experimental database that allows an understanding of important aspects of the spray generated by an airblast atomizer, including atomization and spray propagation, at various ambient pressures is provided. Second, as the control, design or optimization tasks are repetitive and costly, the ability of a recently developed numerical spray module (Sadiki et al. 2005) based on a Euler-Lagrangian method to well capture spray properties under elevated pressure is evaluated. Such a module should help to provide early detailed information at moderate costs of processes under study. The experiments have been performed in a pressure chamber equipped with transparent windows allowing optical access to the spray. By means of PIV technique and Phase Doppler instrument the spray properties have been characterized at various ambient pressures (between 1 and 18 bars). Especially three average velocity components and droplet diameters of the spray have been measured. Numerical studies of the spray transport have been achieved by using advanced URANS-based models. An overall agreement between experimental data and numerical simulation points out the accuracy of the evaluation techniques used for the measurement treatment and demonstrated the prediction ability of the mathematical spray model.