OBJECTIVES: The aim of this study was to better understand the impact of advanced NSCLC and its treatment on the quality of life and experience of patients, in order to inform the design and inclusion of outcome assessments in clinical trials. METHODS: Face-to-face, qualitative, semi-structured interviews were conducted with 20 UK participants with advanced NSCLC. Interviews explored participants’ experiences of aNSCLC and the treatment they received. Open-ended questioning (facilitating spontaneous reporting), was followed by focused questions to further investigate important themes. Creative methods including an impact rating ladder and timeline task were used to elicit content. Verbatim transcripts were analyzed using a data-driven, thematic analysis approach. RESULTS: Participants experienced considerable burden from symptoms and treatment-related side effects (e.g. breathlessness, nausea), which left them unable to participate in activities of daily living such as housework, shopping or going outside. However, participants reported that the emotional impact on them and their families (e.g. worry, sadness and frustration) had the biggest negative impact on their lives. Almost all participants were highly satisfied with their treatment and care, but time lost to receiving and recovering from treatment was commonly reported. Efficiency, communication and practical and emotional support were aspects of care valued most by participants. The majority of participants asked said they would prioritise improving quality of life over extending life. CONCLUSIONS: Advanced NSCLC is known to impact many domains of patients’ lives. This study demonstrates that emotional impact and time taken undergoing treatment may be undervalued by commonly employed HRQoL metrics in clinical trials. Future clinical trials of new lung cancer treatments should include assessment of these concepts. Ultimately, HRQoL instruments should be identified/developed that satisfactorily capture all factors deemed important by patients in order to fully reflect impact of new treatments on patients’ lives.