The goal of the Workshop was to open the way for exchange of ideas between physicists working in different areas of quantum physics but studying the objects of mesoscopic nature which reveal important generic features and allow for similar approaches. Among these objects are complex nuclei, atoms and molecules, nanoscale condensed matter systems, atomic clusters, atoms in traps, prototypes of quantum computers etc. The Workshop WNMP-2004 was organized with the idea of bringing together researchers actively working on the multitude of mesoscopic problems in various areas and, through cross-fertilizing discussions, make an attempt to bridge the existing gaps, find a common language and clean the way for future collaborations. The topics of common interest included general features of mesoscopic systems; experimental, theoretical and computational methods used for their studies; coherent phenomena, such as superfluidity and superconductivity; many-body quantum chaos; marginally stable and open systems; phase transitions and thermodynamic properties (an exciting subject with contradictory opinions reflected in the Proceedings).