This volume constitutes the refereed proceedings of the First International Conference on Rough Sets and Current Trends in Computing, RSCTC'98, held in Warsaw, Poland, in June 1998. The volume presents 82 revised papers carefully selected for inclusion in the proceedings; also included are five invited contributions. The volume is divided in topical sections on rough set methods, statistical inference, grammar systems and molecular computations, logic in rough sets, intelligent control, rough sets in knowledge discovery and data discovery, data mining, evolutionary computation, hybrid methods, etc..