Graphical displays of investigations are increasingly used in clinical care. Summaries of medical records for research or clinical review purposes can generate unmanageably large amounts of data, which may be helpfully summarised and displayed using timelines. During a prospective study of cancer care in primary care, care timelines were generated in Microsoft Visio, using data collected retrospectively from general practice records. Data from primary and secondary care consultations were included. Thirteen timelines were created, which proved valuable in summarising and analysing the data concerning the cases studied. Timelines provide a clear, concise way of displaying large amounts of diverse data, although some selectivity is required to facilitate interpretation. Generation of timelines in the software was time consuming: if they could be automatically generated within clinical IT systems, they would enable clinicians to generate useful summaries of care of complex cases, facilitating care reviews.