This paper deals with the present potential and the future perspectives of a unified booking system in air and short-sea shipping lines.  More precisely, on the basis of the analysis of the existing situation in the demand and supply of combined passenger transport services (air and short-sea) as well as the description of the framework of operational and technical characteristics of the unified booking system, the potential of this new system is analysed.  The new unified booking system in air and short-sea shipping lines will transform not only the quality of the services offered to the passenger but also the competition and complementarity environment of the air and short-sea shipping lines.