This book constitutes the refereed proceedings of the 6th International Conference on Rough Sets and Current Trends in Computing, RSCTC 2008, held in Akron, OH, USA, in October 2008. The 49 revised full papers presented together with 2 keynote papers and 3 special session papers were carefully reviewed and selected from numerous submissions. The papers are organized in topical sections on logical and mathematical foundations, data analysis, data mining, decision support systems, clustering, pattern recognition and image processing, as well as bioinformatics. The three special session papers cover topics such as rough sets in data warehousing, classification challenges in email archiving, and approximation theories: granular computing vs. rough sets.