ABSTRACT BACKGROUND: Suicide rates among lung cancer patients are higher than the general population. This study aims to identify patient and disease characteristics associated with suicide in lung cancer patients. METHODS: We conducted an analysis of subjects with primary lung cancer diagnosed between 1973 - 2008 recorded in the Surveillance, Epidemiology and End Results (SEER) database. RESULTS: Of 871,230 persons diagnosed with lung cancer, 1184 suicides were identified. The rate of suicide did not change considerably over time, with 8.83 compared to 7.17 suicides per 10,000 persons-years in 1973-79 and 2000-09, respectively. The standardized mortality ratio (SMR) of the entire cohort was 4.95, with an SMR of 13.4 within 3 months of a cancer diagnosis. Despite most subgroups having a higher SMR than the general population, a wide variation of suicide risk was seen amongst different subgroups, including histologic type (SMR 1.58 vs 7.28 in bronchoalveolar and small cell carcinoma, respectively). The highest SMR's were found in: males; older age; higher grade tumour; metastatic disease, and patients who did not receive or refused treatment. Despite the higher SMR among metastatic patients, over 50% of suicides occurred in those with locoregional, and potentially curable disease. CONCLUSION(S): Lung cancer patients have a higher risk of suicide compared with the general US population, especially within 3 months of diagnosis. Despite the higher SMR among poorer prognosis patients, a concerning proportion of suicides occur in potentially curable patients, highlighting the need for effective screening strategies to avoid this preventable cause of death.