Introduction: Post-disaster psychosocial support (PSS) is an indispensable element of disaster management. A variety of studies contributed to the development of guidelines, information about guideline implementation, and evidence-based practice, as well as the status of local PSS planning and delivery systems in different European regions. However, the multi-disciplinary nature of the organization of post-disaster PSS requires interprofessional and inter-organizational collaboration, but is presently insufficient institutionalized on individual, organizational, and governmental levels, locally, within the region, and nationally. Aim: Objective of this research is to map the existing post-disaster PSS network in the Netherlands in the context of a terrorism scenario, and to identify probable collaboration problems rooted in weak ties and lack of alignment between actors at different levels. Methods: Focus groups were organized in Belgium, France, Norway, and the United Kingdom to learn from the inter-agency response to recent terrorist attacks. Next, social network analysis methods were used to analyze the structure of the collaborative network for post-disaster PSS in the Netherlands. A scenario-based questionnaire was distributed amongst relevant stakeholders through snowballing methods. Respondents were asked to identify organizations they collaborate with on different PSS activities during the preparedness, acute, and recovery phase. Results: The international focus groups resulted in valuable lessons for the Dutch PSS network. Data collection for social network analysis is currently in progress. Based on previous research we expect limited ties between disciplines during the preparedness phase and during the “registration of affected persons” in the acute phase. Most of the interactions between agencies will be linked to one-stop-shop service delivery, and less to commemorations and health monitoring. Discussion: Lessons from the focus groups, verification of whether or not the expectations are supported by ...