BACKGROUND: Patients admitted for resection of lung tumours frequently experience lengthy delays in diagnosis and preoperative investigations. This study was conducted to quantify this delay between presentation and definitive treatment and to assess the factors responsible for such a delay. METHODS: All patients undergoing lung resection for a tumour at a single surgical unit in 1993 were studied. The date of each consultation, investigation, and referral was identified, and the extent of any delay determined. RESULTS: The mean total delay from presentation to operation was 109 days. Within this period an average of one month occurred before referral to a respiratory specialist who then spent two months investigating the patient. After referral to a surgeon, surgery took place within a mean interval of 24 days. CONCLUSIONS: These delays to definitive treatment appear unacceptable. Points at which the efficiency of the diagnostic process could be improved are discussed. The length of delay did not correlate with tumour stage in this study.