BACKGROUND: Geographical inequalities in lung cancer treatment and patient survival have been described. We hypothesized that lung cancer patients' access to treatment may be influenced by deprivation and the pathway to care. METHODS: Case notes were reviewed for patients resident in south-east London who were registered with lung cancer at the Thames Cancer Registry in 1998. Use of surgery, chemotherapy, radiotherapy or any specific treatment and one-year survival were examined. Analyses were adjusted for age, sex, histology, stage and basis of diagnosis. RESULTS: Data for 695 out of 958 (73%) patients were analysed. Subjects who were initially referred to a specialist in thoracic medicine, surgery or oncology were more likely to receive active treatment (71%) than subjects who were referred to other consultants (51%) or who were admitted as emergencies (42%) (P < 0.0001). CONCLUSION: Socio-economic deprivation was associated with lower rates of treatment and this partly explained variations in survival. Subjects who were referred to specialists were more likely to receive active treatment and treatment patterns varied between first trust attended.