The author discusses the conception of Rhythmic Law in Slovak as a national, linguistic phenomenon and presents his view that Rhytmic law is a (too) narrow term of rhythmicity as a general West Slavic phenomenon. Rhythmic Law is a natural process that generally occurs if a language has fixed stress and a distinctive length. The obsessive preoccupation of the exclusivity of Slovak language as an only West Slavic language with the Rhythmic Law prevents scholars from seeing that the same or very similar phenomena also exist in the Czech language, although they are restricted to only some paradigmatic forms and specific derivative categories, these phenomena are examined and compared with those of Slovak