Background. In chronic graft-versus-host disease (cGvHD), skin fibrosis, contractures, and an increase in collagen content form the hallmark. We report a successful treatment of a cGvHD patient by topical application of halofuginone, an inhibitor of collagen α1(I) gene expression. Methods. Halofuginone-containing ointment was applied daily on the left side of the neck and shoulder of a cGvHD patient. Collagen α1(I) gene expression and collagen content in skin biopsy specimens were evaluated by in situ hybridization and sirius red staining, respectively. Results. After 3 and 6 months, a marked reduction in skin collagen synthesis was observed, accompanied with increase neck rotation on the treated side. After cessation of treatment, the sclerosis, skin tightness, and collagen α1(I) gene expression returned to baseline level. No adverse effects were observed, and no plasma levels of halofuginone could be detected. Conclusions. Halofuginone may provide a promising novel and safe therapy for cGvHD patients.