Adherence to radiotherapy with curative intent is essential for effective cancer treatment, yet non-adherence remains a significant challenge in resource-limited settings. This study assesses the social and clinical factors associated with non-adherence among patients treated at the Regional Institute of Neoplastic Diseases of the Center in Concepción, Junín, Peru. Using a retrospective analytical design, patient records were reviewed to identify cases of treatment interruption, delay, or non-completion. Findings indicate that patients from rural or geographically isolated areas are more likely to experience non-adherence due to transportation difficulties and financial constraints. Clinically, advanced disease stage and treatment-related toxicity were also associated with incomplete radiotherapy. Non-adherence was linked to poorer treatment outcomes, highlighting its impact on survival. The study emphasizes the need for targeted strategies to address both social and clinical barriers in order to improve adherence and optimize cancer treatment outcomes in similar settings