Background: Despite a proliferation of evidence and the development of standardised tools to improve communication at handover, evidence to guide the handover of critical patient information between nursing team leaders in the intensive care unit is limited. Objective: The study aim was to determine the content of information handed over during intensive care nursing team leader shift-to-shift handover. Design: A prospective observational study. Setting: A 21-bed medical/surgical adult intensive care unit specialising in cardiothoracic surgery at a tertiary referral hospital in Queensland, Australia. Participants: Senior nurses (Grade 5 and 6 Registered nurses) working in team leader roles, employed in the intensive care unit were sampled. Method: After obtaining consent from nursing staff, team leader handovers were audiotaped over 20 days. Audio recordings were transcribed and analysed using deductive and inductive content analysis. The frequency of content discussed at handover that fell within the a priori categories of the ISBAR schema (Identify-Situation-BackgroundAssessment-Recommendation) was calculated. Results: Forty nursing team leader handovers were recorded resulting in 277 patient handovers and a median of 7 (IQR 2) patients discussed at each handover. The majority of nurses discussed the Identity (99%), Situation (96%) and Background (88%) of the patient, however Assessment (69%) content was varied and patient Recommendations (60%) were discussed less frequently. A diverse range of additional information was discussed that did not fit into the ISBAR schema. Conclusions: Despite universal acknowledgement of the importance of nursing team leader handover, there are no previous studies assessing its content. Study findings indicate that nursing team leader handovers contain diverse and inconsistent content, which could lead to inadequate handovers that compromise patient safety. Further work is required to develop structured handover processes for nursing team leader handovers.