Over a 5-year study period, 22 patients with isolated lower limb injuries who were immobilized in a plaster cast developed a pulmonary embolus. This information was not available from orthopaedic audit. Better cross-specialty accounting is required if complications that span different hospital specialties are to be fully elucidated. This problem was heightened by the number of emboli occurring while the patient was being treated as an outpatient.