Radiotherapy, a cornerstone of cancer treatment, often leads to significant side effects that can impair a patient’s functional abilities and quality of life. This chapter explores the critical role of rehabilitation in mitigating these side effects and ensuring functional recovery and maintenance across various cancer types. Radiotherapy can cause a range of complications, including tissue fibrosis, muscle weakness, lymphedema, and cognitive deficits, necessitating a comprehensive rehabilitation approach. We begin by highlighting the necessity of rehabilitation for patients undergoing head and neck radiotherapy, where speech, swallowing, and facial functions are commonly affected. For brain radiotherapy, we emphasize cognitive rehabilitation and strategies to manage neurological deficits. Thoracic radiotherapy often impacts respiratory and cardiac functions, making pulmonary rehabilitation essential for restoring lung capacity and overall cardiovascular health. Breast radiotherapy can lead to shoulder dysfunction and lymphedema, necessitating specialized physical therapy interventions. Similarly, gastrointestinal radiotherapy requires targeted rehabilitation to manage bowel dysfunction and nutritional issues. Gynecological and urinary system radiotherapies present unique challenges such as pelvic floor dysfunction, requiring tailored therapeutic exercises and interventions. Hematologic diseases treated with radiotherapy often result in systemic side effects, and sarcoma treatments necessitate comprehensive musculoskeletal rehabilitation. For Kaposi sarcoma, rehabilitation focuses on managing skin lesions and associated mobility issues. Endocrine and ocular system radiotherapies require specialized approaches to address hormonal imbalances and visual impairments, respectively. By detailing the specific rehabilitation needs for each type of radiotherapy, this chapter underscores the importance of an individualized rehabilitation plan to enhance recovery, maintain functionality, and improve the overall quality of life for cancer patients. The integration of rehabilitation into the cancer care continuum is essential for addressing the multifaceted impacts of radiotherapy and ensuring optimal patient outcomesn