Finnish is a highly inflectional language. A verb can have over ten thousand different surface forms - nominals slightly fewer. Consequently, a morphological analyzer is an important component of a system aiming at "understanding" Finnish. This paper briefly describes our rule-based heuristic analyzer for Finnish nominal and verb forms. Our tests have shown it to be quite efficient: the analysis of a Finnish word in a running text takes an average of 15 ms of DEC 20 CPU-time. I INTRODUCTION This paper briefly discusses the application of rule-based systems to the morphological analysis of Finnish word forms. Production systems.