Background. Safe clinical practice for patients during a suicidal crisis is situated within a complex, non-linear and uncertain context. It involves a complex set of practices in which adaptation is perceived as a source of safety. This study aims to develop a deeper understanding of safe clinical practice and the capacity to adapt to challenges and changes in clinical care for patients hospitalised in mental health wards during a suicidal crisis. Methods. This study applied a qualitative design based on focus group and individual interviews. Twenty-five health care professionals (HCPs) participated in the focus groups, and 18 HCPs were individually interviewed. The study was conducted at open and locked wards in a university hospital in Norway that provides specialised mental health services for adults.Findings. Adaptive capacities for clinical practice were described in relation to three themes. 1) HCPs described using expertise to make sense of suicidal behaviour to support complex decision-making. Their strategies relied on setting the checklist aside to prioritise trust and making judgements beyond spoken words. They improved their understanding by seeking others’ perspectives through a collaborative sense-making process involving the health care team and the patient. 2) HCPs reported individualising the therapeutic milieu to address the diversity of patients with suicidal behaviour. Safe clinical practice was provided by creating individual clinical pathways, making trade-offs between under- and over-protection and adjusting observations 3) It was necessary for HCPs manage uncertainty to provide safe clinical practice. They did so as a team by developing mutual collegial trust, support and shared understanding. Conclusion. HCPs’ adaptive capacities are vital to the complex set of practices involved in safe clinical practice for patients hospitalised during a suicidal crisis. By using expertise, individualising the therapeutic milieu, and managing uncertainty, HCPs individually and collectively develop their capacity to adapt to challenges and changes in clinical care. Safe clinical practice cannot easily be ensured by following standards; it depends on HCP adaptations. Ward systems ensuring collegial trust and support are needed, as are arenas supporting shared understanding and collaborative sense-making. Keywords: Adaptation, sense-making, situational awareness, shared understanding, trade-offs, mental health, suicide, uncertainty