: Lung cancer is one of the commonest cancers to cause pain, but little is known regarding the extent of this complex problem in these patients. Methods: Medline (1966–June 2002) and Cancerlit (1975–May 2002) were searched to identify studies of lung cancer patients’ experience of pain, its prevalence, causes and underlying pathophysiology. Results: Thirty-two studies were identified. Patients were recruited from diverse populations, and the prevalence varied according to study setting. Pain affected 27% of outpatients (range 8–85%), and 76% of patients cared for by palliative care services (range 63–88%). Pain was caused by cancer in 73% (range 44–87%), and cancer treatment in 11% (range 5–17%). Nociceptive pain was the major pathophysiological subtype in lung cancer pain, but neuropathic pain accounted for 30% (range 25–32%) of cases. Conclusions: The overall weighted mean pain prevalence of pain was 47% (range 6–100%). Cancer patients should be asked about pain at all stages of management. Those with pain should be investigated for disease progression and considered for referral for specialist management.