Background: Unplanned admissions of intensive care patients demand well-organised team work. Lack of an intensive care unit (ICU) admission protocol may lead to insufficient preparations or unclear task allocations. It was hypothesised that using a Lean approach, the organisation and perceived quality of care of unplanned ICU admissions could be improved. Methods: Using Lean, the organisation of unplanned admissions was analysed by measuring the perception of the quality of care amongst physicians and nurses. These results led to a new protocol describing logistical and organisational measures. After six months of implementation, a survey was performed to evaluate the effect using a modified t-test. Results: After implementation, 27 questionnaires were filled in and compared with 27 baseline questionnaires. The satisfaction of nurses with the quality of admission, expressed in the admission score (M, on a scale of 1-10) improved (pre: M=7.4; SD=1.3; post: M=8.2; SD=0.9; p=0.001). On a scale of 1-5 the score for clear task allocation improved (pre: M=3.3; SD=1.2; post: M=4.3; SD=0.9; p < 0.001) as well as the score for effective communication (pre: M=4; SD=0.8; post: M=4.4; SD=0.7; p=0.01). Physicians reported an improvement in the score for clarity about task allocation (pre: M=3.2; SD=1.2; post: M=4.1; SD=1.3; p=0.001) and the content of task (pre: M=3.6; SD=1.1; post: M=4.1; SD=1; p=0.001). Conclusion: By using a Lean approach, the implementation of a survey-based protocol resulted in a perceived improved quality of unplanned admissions at the ICU. © 2020, Netherlands Society of Intensive Care. All rights reserved.