Background As a protective factor, social support can influence benefit finding (BF) in patients with advanced lung cancer. However, the mechanism through which social support affects BF is controversial. Objective To investigate the factors influencing BF in patients with advanced lung cancer and the role of hope level in mediating the relationship between social support and BF. Methods This was a cross-sectional study. From September 2022 to March 2023, 286 participants completed the Social Support Rating Scale, Herth Hope Index, and Benefit Finding Scale. Data analysis included correlation analyses and multiple stepwise regression analysis; the SPSS PROCESS program was used to determine the significance of mediating effects. Results Social support and hope level were positively associated with BF. Monthly per-capita household income, social support and hope level entered the final regression model and explained 50.7% of BF variance. Social support’s direct and indirect effects on BF were significant ( P < .05), suggesting that hope level partially mediated the relationship between social support and BF. Conclusion Our findings validate a positive association between social support and BF in patients with advanced lung cancer. The hope level as a mediating variable provided the impetus for their BF. Implications for practice Nurses should implement necessary interventions to help patients with advanced lung cancer carry out protective resources and coping strategies to facilitate their BF.