This book constitutes the refereed proceedings of the Second International Bioinformatics, WABI 2002, held in Rome, Italy, in September 2002.The 39 revised full papers presented together with an full invited paper were carefully reviewed and selected from 83 submissions. Among the topics addressed are exact and approximate algorithms for genomics, genetics, sequence analysis, gene and signal recognition, alignment, molecular evolution, phylogenetics, structure determination and prediction, gene expression and gene networks, proteomics, functional genomics, and drug design.