Objectives This study examined how one large blood-related establishment coped and adapted during the first 1.5 years of the pandemic by evaluating the impacts and changes on its resources, communication, collaborations, and monitoring and feedback. Furthermore, we explored whether elements of complexity leadership emerged during this time. Design Duchek’s organisational resilience framework was primarily used. We followed a three-step sequential approach: (1) a document analysis of over 150 intranet, internet and internal reports; (2) 31 semistructured interviews with employees and (3) four feedback sessions. Setting Sanquin is known as the Dutch national blood bank and a large multidivisional expertise organisation in the Netherlands. Results Sanquin coped well. Respondents accepted the crisis and catalysed many collaborations to implement solutions, which were communicated to the public. There were many positive aspects related to internal collaborations, yet challenges remained related to its historical siloed structure and culture. Sanquin adapted partially. Many respondents experienced the organisation becoming more connected and flexible during the pandemic. However, Sanquin was not permanently changed due to significant leadership changes and organisational restructuring occurring simultaneously. Respondents reflected on lessons learnt, including the need for continual collaboration and improvements in Sanquin’s culture. An important driver in the successful coping was management’s enabling attitude and the adaptations occurring within and through the collaborative groups. Conclusions Sanquin improved its organisational resilience by exhibiting elements of adaptive spaces, enabling leadership and (temporary) emergence from complexity leadership. This illuminates how the organisation could continue benefiting from complexity leadership for non-crises and for future uncertainties.