Seven patients (4 female and 3 male, mean age 46) with arthritis of the wrist (n = 7) without known etiology were evaluated. High-definition ultrasound equipment was used for localization of synovial hypertrophy, suitable for ultrasound guided biopsy without risk. A 18-gauge diameter Tru-cut biopsy needle was used in an automated gun. Two passes were performed with continuous guidance of the needle-tip. In all patients representative synovial tissue was obtained in adequate amount. No complications were encountered. Ultrasound guided biopsy is proposed as an effective technique which can be performed with low patient discomfort on an outpatient basis.