This book constitutes the refereed proceedings of the 9th International Meeting on Computational Intelligence Methods for Bioinformatics and Biostatistics, CIBB 2012, held in Houston, TX, USA during in July 2012. The 16 revised full papers presented were carefully reviewed and selected from 23 submissions. The papers are organized in topical sections on relativistic heavy ions and DNA damage; image segmentation; proteomics; RNA and DNA sequence analysis; RNA, DNA, and SNP microarrays; semi-supervised/unsupervised cluster analysis.