There is controversy whether high-dose therapy and a bone marrow autotransplant or conventional chemotherapy is a better treatment for newly diagnosed multiple myeloma. Data from 1 comparative study and 1 randomized trial provide insufficient subject-level data to advise specific people whether to have an autotransplant. We analyzed appropriate use of high-dose therapy and bone marrow autotransplants in people with newly diagnosed, multiple myeloma using a modified Delphi-panel group judgment process. The panel consisted of 9 myeloma experts from diverse geographic sites and practice settings who reviewed Boolean MEDLINE searches of multiple myeloma and chemotherapy or autotransplants. The panel rated a metric of 64 clinical setting developed by permuting age, performance score, disease-stage and disease-related prognostic variables and response to initial therapy. Each panelist rated appropriateness of high-dose therapy and an autotransplant versus conventional-dose chemotherapy on a 9-point ordinal scale (1, most inappropriate, 9, most appropriate). An appropriateness index was developed based on median rating and amount of disagreement. Relationship of appropriateness indices to the permuted clinical variables was considered by analysis of variance and recursive partitioning. Autotransplants were rated appropriate in persons <55 years old with stage 3 disease and a complete or partial response or stable disease after initial chemotherapy, inappropriate in persons with stage 1 or 2 disease, a performance score <70% and a complete or partial response or stable disease after initial chemotherapy and uncertain in all other settings.