Psychological distress while coping with cancer is a highly prevalent and yet underrecognized and burdensome adverse effect of cancer diagnosis and treatment. Left unaddressed, psychological distress can further exacerbate poor mental health, negatively influence health management behaviors, and lead to a worsening quality of life. This multimethod study primarily focused on understanding veterans' psychological distress and personal experiences living with lung cancer (an underrepresented patient population). In a sample of 60 veterans diagnosed with either nonsmall cell lung cancer (NSCLC) or small cell lung cancer (SCLC), we found that distress is common across clinical psychology measures of depression (37% [using the Patient Health Questionnaire, PHQ-9 measure]), anxiety (35% [using the Generalized Anxiety Disorder, GAD-7 measure]), and cancer-related posttraumatic stress (13% [using the Posttraumatic Stress Symptom Checklist measure]). A total of 23% of the sample endorsed distress scores on two or more mental health screeners. Using a broader cancer-specific distress measure (National Comprehensive Cancer Network), 67% of our sample scored above the clinical cutoff (i.e., ≥ 3), and in the follow-up symptom checklist of the National Comprehensive Cancer Network measure, a majority endorsed feeling sadness (75%), worry (73%), and depression (60%). Qualitative analysis with a subset of 25 veterans highlighted that psychological distress is common, variable in nature, and quite bothersome. Future research should (a) identify veterans at risk for distress while living with lung cancer and (b) test supportive mental health interventions to target psychological distress among this vulnerable veteran population. (PsycInfo Database Record (c) 2024 APA, all rights reserved).