Art Nouveau was a short-lived European phenomenon in art and architecture. Despite the fact that Art Nouveau architecture never fully succeeded as an anti-historical movement, it is important to identify its place in modern architectural historiography. The significance of Art Nouveau-that it incorporated decorative elements into the centre of architectural practice-certainly serves to acknowledge its place within the Modern Movement. Architectural works of Victor Horta, Hector Guimard and Charles Rennie Mackintosh are carefully examined in this paper to find out (1) how they individually emerged and manifested distinctive characteristics and creativity within their own local contexts, and (2) how they can collectively fit into historical discourse of Art Nouveau. Art Nouveau was not a mere fin-de-ci cle phenomenon, but a complicated transient phase at the dawn of European Modernism.