This book constitutes the refereed proceedings of the 5th International Conference on Rough Sets and Current Trends in Computing, RSCTC 2006, held in Kobe, Japan in November 2006.

The 91 revised full papers presented together with 5 invited papers and 2 commemorative papers were carefully reviewed and selected from 332 submissions. The papers are organized in topical sections on logics in rough sets, logics in fuzzy sets, fuzzy-rough hybridization, approximate and uncertain reasoning, variable precision rough set models, incomplete/nondeterministic information systems, decision support, multi-criteria decision support, rough sets in KDD, rough sets in medicine, granular computing, grey systems, ontology and mereology, statistical methods, machine learning, clustering, data mining, evolutionary computing, intelligent information systems, pattern recognition and image processing, as well as data clustering: algorithms and applications.