This volume contains a selection of invited papers, presented to the fourth International Conference on Statistical Data Analysis Based on the L1-Norm and Related Methods, held in Neuchatel, Switzerland, from August 4-9, 2002. The contributions give evidence of the importance of development of theory, methods and applications related to the statistical data analysis based on the L1-norm. Covering a broad range of topics around statistical data analysis, the contents are intended as a resource for researchers, practitioners and industrial statisticians. Several contributions can also be used by financial economists, environmental engineers and professionals in image processing.