th Thisvolumecontainsaselectionofthebestcontributionsdeliveredatthe6 - ternational Meeting on Computational Intelligence Methods for Bioinformatics andBiostatistics(CIBB2009)heldatOratorioSanFilippoNeriinGenoa(Italy) during October 15-17, 2009. TheCIBBmeetingseriesisorganizedbytheSpecialInterestGrouponBio- formatics of the International Neural Network Society (INNS) to provide a - rum open to researchers from di?erent disciplines to present and discuss pr- lems concerning computational techniques in bioinformatics, systems biology and medical informatics with a particular focus on neural networks, machine learning, fuzzy logic, and evolutionary computational methods. From 2004 to 2007,CIBB meetings wereheld with an increasing number of participants in the formatof a specialsessionofbigger conferences,namely, WIRN 2004in Perugia, WILF 2005 in Crema, FLINS 2006 in Genoa and WILF 2007 in Camogli. With the great success of the special session at WILF 2007 that included 26 strongly ratedpapers,welaunchedthe?rstautonomousCIBBconferenceeditionstarting with the 2008 conference in Vietri. CIBB2009attracted57papersubmissionsfromallovertheworld. Arigorous peer-reviewselectionprocesswasappliedtoultimatelyselectthepapersincluded in the program of the conference. This volume collects the best contributions presentedattheconference. Moreover,thevolumealsoincludes onepresentation from keynote speakers and two tutorial presentations. The success of CIBB 2009 is to be credited to the contribution of many people. Firstly, we would like to thank the organizers of the special sessions for attracting so many good papers which extended the focus of the main topics of CIBB. Second, special thanks are due to the Program Committee members and reviewers for providing high-quality reviews.