BACKGROUND:The advice on hair washing during brain irradiation is aimed at minimizing radiation induced skin toxicity. We performed a prospective randomized trial to assess the effect of advice on scalp care on the local skin reaction in patients undergoing cranial radiotherapy. METHODS:One hundred and nine patients undergoing cranial radiotherapy were randomized into two groups. Patients in group 1 were advised not to wash hair during treatment and patients in group 2 to maintain normal pattern of hair washing. They were assessed weekly over a period of 10 weeks from the start of treatment. Symptoms of pain and itching were recorded using a modified RTOG/EORTC acute skin reaction scoring system and skin reaction was assessed clinically using erythema/desquamation score. The frequency of hair washing and the distress of changing the practice of normal hygiene were recorded on a diary card. Skin reaction scores were compared as a summary measure using area under the curve per week (AUC/week) and median scores, and the differences between groups were assessed by means of the t-test. RESULTS:One hundred and nine patients commencing cranial radiotherapy according to standard protocol were randomized into the trial (group 1, 55 patients; group 2, 54 patients). Patients asked to restrict hair washing, washed at a lower average frequency. There were no significant differences between scores of skin reaction in the two groups for each of the variables measured. CONCLUSIONS:The practice of normal hair washing is not associated with increased severity of adverse skin reaction. As a request to change the pattern of normal hygiene may cause distress, the current advice should be to maintain normal hair washing during cranial radiotherapy.