Inter-organisational knowledge sharing between airport security organisations has become increasingly vital to maintain the highest standards of security and public safety. Social networks are considered a significant space for knowledge sharing within and across organisations. The purpose of this research is to investigate inter-organisational knowledge sharing in social media between key organisations in policing and airport security. A cross-sectional case study strategy combining qualitative and quantitative methods was employed to investigate the use of social media in inter-organisational knowledge sharing in the context of airport security in the UAE. Findings showed that the structural characteristics within knowledge sharing were highly centralised and polarised with low intensity in knowledge sharing. Social capital was constrained at a relational level due to cultural factors of trust, risk aversion and power distance that influenced a closed culture and reduced the scope for tacit knowledge sharing practices as well as low level cognitive capital. Analysis of dimensions of the SECI model for knowledge creation revealed that knowledge and the process of knowing was impacted by cultural distinctions that constrained socialisation, externalisation, combination and internalisation processes. The key barriers to knowledge sharing were identified and associated with trust, risk aversion, organisational culture, resource constraints and interoperability factors. This study makes a contribution to theory and practice in terms of the relationship between social capital dimensions and knowledge creation processes and the characteristics of knowledge-sharing within social media. The study further adds to knowledge on the antecedents of inter-organisational knowledge sharing, particularly in the Arabic context. / UAE Government and Ministry of Interior