The study aims to investigate the influence of inter-organizational knowledge sharing enablers-communication, trust, shared vision, commitment, learning intent, and absorptive capacity directly and indirectly through inter-organizational knowledge sharing process on behavioural innovation outcome in strategic alliances of 4- & 5-stars hotels of world heritage cities of Istanbul and Antalya. For data collection, the quota sampling method is applied to select the 250 senior hotel executives engaged in collaborative strategic hospitality alliances. Besides, to test the hypotheses, descriptive, correlation as well as regression analyses are performed through the SPSS. The current study finds that the six facets of relational and social capital inter-organizational knowledge sharing enablers offered and examined have significant impacts, directly and indirectly through inter-organizational knowledge sharing process on the innovative behavioural outcome of hospitality alliance firms. The results imply that the hospitality industry in its policy agenda should recognize that relational and social capital-based knowledge sharing strategic alliances can be a vital source of collaborative innovation. Finally, the current research also provides the empirical recognition of historic cities of Turkey as cultural destinations, so emphasizing the appropriateness of world heritage cities to investigate inter-firm relationships across hospitality alliance firms.