The non-reactive diesel spray is studied in a constant volume combustion chamber. Droplet sizes and velocities are measured using Particle Doppler Analyzer instrumentation. The effects of aerodynamic drag and vaporization on the droplets size are emphasized. An increase of the mean diameters is observed downstream of the break-up region.The well known KIVA-II code is used to achieve spray computations. The break-up model is disabled and the spray is assumed to be already atomized at the nozzle exit. Size distribution and velocities of the injected droplets are deduced from downstream experimental data.A good agreement is obtained between numerical and experimental results. Size distributions at various locations and temperature conditions are correctly predicted. A diesel spray can be thus modeled in a satisfactory way, when we alleviate the complex processes of break-up, but with appropriate initial droplets conditions.