Appeared in the XIX century, summer mountain tourism has a very strong capital attraction for international tourist flows and constitutes the basis of leisure tourism. However, for the last several years numerous, mature Alpine destinations in particular have been losing overnight stays during summer months by cause of competition with winter tourism as well often from warmer, cheaper and more easily accessible beach destinations. Moreover, due to the globalisation pressure, summer mountain tourism development is strongly dependent on structural change in "21st century post-modern" tourist demand. Thus, innovative tourism product development has become a central key issue for many Alpine tourism organisations. The aim of this paper is to present the result of explanatory research conducted in 2014 and 2015 in four Alpine countries. The research objective was to evaluate the role of 125 Destinations Management Organizations (DMOs) in the stimulation of summer tourism through the commercialization of various tourism products.