This book constitutes the proceedings of the 6th Brazilian Symposium on Bioinformatics, BSB 2011, held in Brasilia, Brazil, in August 2011. The 8 full papers and 4 extended abstracts presented were carefully peer-reviewed and selected for inclusion in this book. The BSB topics of interest cover many areas of bioinformatics that range from theoretical aspects of problems in bioinformatics to applications in molecular biology, biochemistry, genetics, and associated subjects."