Background: Latino cancer patients face disparities in prognostic understanding due to lack of culturally competent communication around prognosis and advance care planning (ACP). Objective: To examine Latino patients’ understanding of prognosis in advanced, terminal cancer, and how cultural factors influence this understanding and ACP engagement. Methods: Mixed methods study with surveys and semi-structured interviews; descriptive statistics and thematic content analysis were used. Findings: Among 20 Latino patients with advanced cancer, 50% inaccurately believed they had early-stage cancer, 85% did not believe their cancer was terminal, and 70% believed it was curable. Interviews revealed two themes: (1) varying awareness of incurability and (2) diverse end-of-life decision-making and treatment preferences. Patients expressed denial or acceptance of prognosis through communication with oncologists, family importance, and pre-existing beliefs. Conclusion: Communication, family involvement, and incorporation of beliefs are key to promoting accurate prognostic understanding and addressing disparities in Latino advanced cancer patients’ engagement in end-of-life care decision-making.