The 21st IIR Congress of Refrigeration, held in Washington DC on August 17-22, 2003, gave scientists and engineers an opportunity to work with their colleagues from around the world and share ideas that may shape refrigeration technology for decades to come. With ‘Serving the Needs of Mankind’ as its theme, over 750 people from 58 countries attended this important event. Almost 440 papers by 1031 authors from 46 countries were presented at the Congress. Many of them had to do with new technology; e.g. CO2 systems, advanced heat exchange techniques, absorption systems, and cold chain. All papers are included on this Congress proceedings CD ROM.