Ventilation and perfusion lung scintigraphy is an established and safe noninvasive technique which has been used for nearly 30 years to establish the diagnosis of pulmonary embolism. Recently, in common with other diagnostic tests, there has arisen the need to reassess the effectiveness of this test in the clinical setting. A retrospective analysis of 244 patients undergoing ventilation-perfusion lung scintigraphy was performed. A total of 203 case notes were available. It was found that the majority of reports (68.5%) were described as either high probability for the presence of pulmonary embolism or normal or low probability. A result of 'high probability' changed the clinical management of the patient in 28/46 (61%) of reported cases but in only 5/91 (5.5%) of patients reported as 'normal' or 'low probability'. During the study there were six deaths, five from other causes and one from pulmonary embolism; this patient died despite anticoagulation following a 'high probability' ventilation-perfusion lung scintigraphy. Ventilation-perfusion lung scintigraphy is a safe and effective noninvasive method to diagnose the presence of pulmonary embolism and a test which has a significant effect on patient management.