© 2016 Hanley & Belfus Study Design Cross-sectional descriptive study. Introduction Osteoarthritis (OA) is the most prevalent musculoskeletal disease in the adult and older adult populations. The use of orthoses to stabilize the thumb's articular complex is one of the most common conservative management strategies. Despite substantial research about this topic, there is insufficient evidence about the optimal use of orthoses to inform clinical practice, contributing to practice variations within and across health professionals. Purpose of the Study To identify the prescription patterns, design preferences, and barriers for the use of orthotic devices among Brazilian health care professionals involved in the treatment of patients with OA of the basal thumb joint. Methods An electronic questionnaire was sent to occupational therapists, physiotherapists, and rheumatologists across Brazil through professional association mailing lists. Survey included questions about orthosis design, materials, and barriers to the use of orthotic interventions. Respondents indicated their use based on photographs of 25 orthoses models that were selected through bibliographic review and expert consultation. Descriptive statistics, the chi-square test for independence, and the Fisher exact test were used to compare differences among orthotic prescription preferences, barriers, and challenges observed amidst the 3 participants' professional classes. Results There was no consensus about orthotic prescription among 275 professionals who answered the survey. About 69% of participants reported the use of multiple orthosis during treatment of patients with thumb OA. Results suggest significant variations in the number of joints included and stabilization strategies adopted, with a preference for orthotics made in rigid materials and involving the wrist, carpometacarpal, and metacarpophalangeal joints (P < .001). The lack of knowledge about orthotic options, institutional regulations, and policies were the major barriers reported by respondents (P < .01). Conclusion A plentiful variety of different orthoses designs were observed in this study, and the prescriptions made by 3 professional classes showed differences regarding types of stabilization, joint involvement, and positioning. Despite the existence of clinical trials suggesting benefits for specific custom-made design models, our results indicated widespread clinical variation in practices and preferences. Level of Evidence Not applicable.