To develop a practice guideline report on the questions: What are the optimal methods to prevent acute skin reactions (occurring within the first 6 months of irradiation) related to radiation therapy? What are the optimal methods to manage acute skin reactions related to radiation therapy? Cancer Care Ontario's Supportive Care Guidelines Group (SCGG) conducted a systematic review of literature on this topic. Evidence-based recommendations were formulated to guide clinical decision making, and a formal external review process was conducted to validate the relevance of these opinions for Ontario practitioners. Twenty-eight trials meeting the inclusion criteria were identified. Of the twenty-three trials that evaluated preventative methods, washing was the only practice which significantly prevented skin reaction. Some evidence suggested topical steroid creams and calendula ointment might be effective. None of the five trials evaluating skin reaction management detected a positive effect using steroid cream, sucralfate cream, or dressings. Skin washing, including gentle washing with water alone with or without mild soap, should be permitted in patients receiving radiation therapy to prevent acute skin reaction. There is insufficient evidence to support or refute specific topical or oral agents for the prevention or management of acute skin reaction. In the expert opinion from the SCGG, the use of a plain, non-scented, lanolin-free hydrophilic cream may be helpful in preventing radiation skin reactions. In addition, a low dose (i.e., 1%) corticosteroid cream may be beneficial in the reduction of itching and irritation.