Purpose <p>This study aimed to investigate the prevalence and characteristics of burnout among Radiation Oncology residents in Spain, focusing on its associated risk factors and implications for residency training.</p> Materials and methods <p>A cross-sectional online survey was conducted from June to September 2024, using the Maslach Burnout Inventory (MBI) to evaluate emotional exhaustion, depersonalization, and self-fulfillment. Residents from various Spanish regions completed an anonymous questionnaire covering workload and burnout.</p> Results <p>Fifty residents, predominantly in their third (38%) and fourth (42%) years of training, participated. High emotional exhaustion was reported by 58%, while 54% exhibited elevated depersonalization. Self-fulfillment scores were low in 32%. Overall, 70% experienced at least one burnout symptom, with 12% meeting criteria for full-burnout syndrome. An inverse correlation between self-fulfillment and emotional exhaustion was observed (<i>p</i> = 0.007). Trends suggested higher burnout risk in senior residents (R3-R4) compared to juniors (R1-R2), though these differences were not statistically significant (OR = 1.682; <i>p</i> = 0.086).</p> Conclusion <p>The findings reveal a high prevalence of at least one burnout symptom among Radiation Oncology residents in Spain, with emotional exhaustion and depersonalization notably elevated. However, full-burnout syndrome is not prevalent. These findings underscore the need for reforms in residency training programs, emphasizing workload management, well-being initiatives, and support for scientific and professional development.</p>