Aim: This study aims to report distress experienced by patients and their natural caregivers early after the diagnosis of inoperable lung cancer.Methods: A survey on patients recently diagnosed with inoperable lung cancer and their natural caregivers is being conducted in Quebec City (Quebec, Canada). They completed validated questionnaires regarding their sociodemographics and psychosocial characteristics (HADS, IDPESQ). Univariate, bivariate analyses and multiple regression were conducted. Results: A total of 154 patients and 95 natural caregivers have participated to this survey so far. Surprisingly, patients’ distress scored low with the IDPESQ instrument (12.4 ± 11.3 on a scale of 0 to 100), and only 9.1% of them reported significant distress with the HADS (total score ≥ 15 on a scale of 0 to 42). In contrast, natural caregivers reported significantly higher distress (IDPESQ score: 22.9 ± 16.2; p<0.0001) and 34.7% of them presented significant distress according to HADS scores (p < 0.0001). For patients, age<65 (p=0.02), female gender (p=0.001) and smaller social network (p=0.02) were associated with significant distress, but delay since diagnosis, functional status, recurrence of cancer, metastasis and cancer treatment had no influence on distress. For natural caregivers, perception of higher burden of care (p<0.0001) and shorter delay since diagnosis (p=0.0037) were significant predictors of distress, while age and gender were not associated with it. Conclusion: The diagnosis of cancer seems to initially impact more on natural caregivers than on patients. These findings reinforce the importance, in the patients’ initial global need assessment, of early assessing and managing natural caregivers’ distress, as they are key partners in patient support and care throughout the cancer journey. Funding: This study is funded by the Canadian Cancer Society-Ontario Division.