The Workshop is being organized since 1997. First its principal goal was to serve as a seminar on physics of phase transitions and critical phenomena. The seminar aimed in promoting and deepening studies of critical phenomena as well as in exchanging information between scholars working in this field. Gradually, the principal scope of the Workshop turned into a more general context of complex systems, i.e. systems composed of many interacting parts which display collective behavior that does not follow trivially from the behaviors of the individual parts. The level of presentation and its interdisciplinarity allows for participation of physics students and academics working in different areas. Both review lectures as well as reports on original work (in English or in Ukrainian) are welcome.