This book constitutes the thoroughly refereed post-conference proceedings of the Fifth International Meeting on Computational Intelligence Methods for Bioinformatics and Biostatistics, CIBB 2008, held in Vietri sul Mare, Italy, in October 2008.The 23 revised full papers presented together with 3 invited lectures were carefully reviewed and selected from 69 submissions. The main goal of the CIBB meetings is to provide a forum open to researchers from different disciplines to present and discuss problems concerning computational techniques in bioinformatics, systems biology and medical informatics with a particular focus on neural networks, machine learning, fuzzy logic, and evolutionary computation methods.