An electromechanical tremor scoring device (TSD) that provides an immediate score of tremor severity was compared with clinical assessment in 18 multiple sclerosis (MS) patients with tremor, and 8 normals. The TSD consists of a hinged brace that allows only wrist motion, a potentiometer that serves as a wrist angle transducer, and a light-emitting diode display. On the display appear two linear traces: a pseudorandomly moving target and a wrist transducer signal. The subject attempts to align the wrist with the target signal for 100 seconds. The device determines the absolute voltage difference between the signals, producing an error score. The device is compact and portable. Clinical assessments were performed independently by two neurologists; clinical characteristics of tremor severity were rated and a composite score was obtained. TSD scores and clinical ratings were compared. TSD scores differentiated MS patients (mean, 414.1) from normals (mean, 143.3). The test-retest reliability of the TSD was 0.92. The inter-rater reliability of the clinical composite was 0.74. The correlation between the TSD and the clinical composite was 0.72. Results suggest that the TSD may provide a quick, valid, and reliable technique for tremor measurement.