This thesis explores different aspects of Horizontal Logistics Collaboration (HLC) to increase our understanding of how to successfully implement it. The research draws on theories and concepts from different areas of operations management and makes use of different methodological approaches to capture the multidimensional aspect of HLC. The results show that HLC can take different forms, with each form resulting in specific operational requirements in terms of the types of assets to share and the kind of information to exchange. In addition, the research indicates that HLC outcomes, which are measured by the partners’ satisfaction, are affected by operational factors (e.g. information sharing, joint relationship efforts) through the mediation of relational factors (e.g. trust and commitment). The relationship between these factors is influenced by the characteristics of the industry and country in which the collaboration in undertaken. Finally, the conducted research reveals the existence of several barriers that limit the development of collaborative behaviour and decreases the collaboration chances to succeed.