BACKGROUND: The lack of standardization of clinical diagnostic criteria, classification and severity scores of chronic graft-versus-host disease led the National Institutes of Health to propose consensus criteria for the purpose of clinical trials. METHODS: Here we describe a one-day workshop model conducted by the Chronic Graft-versus-Host Disease Brazil-Seattle Consortium Study Group to train investigators interested in participating in multicenter clinical trials in Brazil. Workshop participants included eight transplant physicians, one dermatologist, two dentists, three physical therapists and one psychologist from five institutions. Workshop participants evaluated nine patients with varying degrees of severity of mucocutaneous lesions and other manifestations of the disease followed by a training session to review and discuss the issues encountered with the evaluation and scoring of patients and in the methods used to evaluate grip strength and the 2-minute walk test. RESULTS: Most participants had difficulties in rating the percentage of each type of mucocutaneous lesion and thought 20 minutes was insufficient to evaluate and record the scores of each patient using the National Institutes of Health criteria and other cutaneous assessments. Several specific areas of difficulties encountered by the evaluators were: 1) determining the percentage of erythema in movable and non-movable sclerosis, 2) whether to score all cutaneous findings in a particular area or just the dominant lesion; 3) clarification of the definition of poikiloderma in chronic graft-versus-host disease; 4) discrepant interpretation of the mouth score and 5) clarification on the methodology used for the evaluation of grip strength and the 2-minute walk tests. CONCLUSIONS: Results of this workshop support the need to train investigators participating in clinical trials on chronic graft-versus-host disease.