Radiotherapy is, besides surgery and chemotherapy, an established modality in the treatment of breast cancer and genital malignancy in the females as well as prostate cancer in the males. Ionizing radiation may cause post-radiation dermatitis of varying severity. This may result in itching, pain, burning, epithelial exfoliation and inflammatory reaction, which may considerably compromise the patients’ quality of life during radiotherapy, sometimes even necessitating interruption of treatment. In view of such a serious side effect of radiotherapy, protection of irradiated skin and treatment of radiation-induced skin lesions are an important task, both for radiotherapists and for their patients. Preventive measures and treatment of radiation-induced skin reaction should begin on the first day of radiotherapy and continue for several (at least three) months after its termination. Non-compliance may result in exacerbation of radiation-induced lesions, longer healing of skin damaged by ionizing radiation and, in extreme cases, may lead to ulcerations, scars and skin necrosis. Effective care of skin areas exposed to radiotherapy includes wearing proper undergarments and dress, appropriate daily hygiene and avoidance of overheating. We recommend the use of proper dermocosmetics, which facilitate skin regeneration and accelerate healing, i.e. exerting a soothing, hydrating, nourishing, protecting and radiation-induced reaction-alleviating effects. This paper reviews current principles of care of irradiated skin – the key factor in prevention and treatment of radiation dermatitis.