Multi-species laser based imaging measurements were carried out in a reacting Diesel spray to provide a detailed data base for model development and validation. In a high-pressure high-temp. spray chamber the measurements addressed the fuel vapor concn., ignition and flame development and the soot formation. The fuel vapor distribution was measured quant. by Rayleigh scattering and compared to measurements by tracer laser-induced fluorescence. Soot vol. fractions were obsd. by laser-induced incandescence. Fuel vapor and soot distributions were measured simultaneously and provide insight in the ignition and pollutant formation process. Specific digital image processing algorithms were developed to correct for beam steering and laser attenuation.