The aim of this study was to determine the effectiveness of granulocyte-macrophage colony-stimulating factor (GM-CSF) impregnated gauze in preventing or healing radiation-induced dermatitis. Sixty-one patients were irradiated for vulvar carcinoma. Thirty-seven applied steroid cream at irradiated areas throughout radiotherapy (Group A) and 24 patients applied additionally GM-CSF impregnated gauze (40 micrcog/cm2 of skin-irradiated area, twice per day) in addition to the steroid cream, after 20 Gy of irradiation (Group B). The score of skin reactions (P=0.008, chi2 test) and the time interval of radiotherapy interruption (P=0.037, Mann-Whitney U test) were statistically significantly reduced in Group B patients. Multivariate analysis of variance showed for this group not only a significant reduction in the Sum of Gross Dermatitis Scoring (P<0.001, adjusted for Duration of Dermatitis) but also a significant reduction of the healing time (P=0.02, adjusted for Sum of Gross Dermatitis Scoring). The pain grading was less (P=0.014, chi2 test) and pain reduction was noticed sooner after the application of GM-CSF impregnated gauze (P=0.0017, Mann-Whitney U test). Multivariate logistic regression analysis showed that the only significant effect on dermatitis score is due to Body Mass Index (P=0.034) and the application of GM-CSF (P=0.008). GM-CSF impregnated gauze can be effective in preventing and healing radiation-induced dermatitis and in reducing the interruption intervals of radiotherapy for vulvar carcinomas.