Standardising handover processes and content, and using context-specific checklists are proposed as solutions to mitigate risks for preventable errors and patient harm associated with clinical handovers.Adapt existing tools to standardise nursing handover from the intensive care unit (ICU) to the cardiac ward and assess patient safety risks before and after pilot implementation.A three-stage, pre-post interrupted time-series design was used. Data were collected using naturalistic observations and audio-recording of 40 handovers and focus groups with 11 nurses. In Stage 1, examination of existing practice using observation of 20 handovers and a focus group interview provided baseline data. In Stage 2, existing tools for high-risk handovers were adapted to create tools specific to ICU-to-ward handovers. The adapted tools were introduced to staff using principles from evidence-based frameworks for practice change. In Stage 3, observation of 20 handovers and a focus group with five nurses were used to verify the design of tools to standardise handover by ICU nurses transferring care of cardiac surgical patients to ward nurses.Stage 1 data revealed variable and unsafe ICU-to-ward handover practices: incomplete ward preparation; failure to check patient identity; handover located away from patients; and information gaps. Analyses informed adaptation of process, content and checklist tools to standardise handover in Stage 2. Compared with baseline data, Stage 3 observations revealed nurses used the tools consistently, ward readiness to receive patients (10% vs 95%), checking patient identity (0% vs 100%), delivery of handover at the bedside (25% vs 100%) and communication of complete information (40% vs 100%) improved.Clinician adoption of tools to standardise ICU-to-ward handover of cardiac surgical patients reduced handover variability and patient safety risks. The study outcomes provide context-specific tools to guide handover processes and delivery of verbal content, a safety checklist, and a risk recognition matrix.