To study the utility of a new computerized motor-skill analyser (CMSA) for evaluating visuo-motor skilled movements of the arm, we examined (1) the reproducibility of measurement with the CMSA for the arm in 13 healthy participants and 14 patients with stroke and (2) the correlation between motor skills of the affected arm evaluated with the CMSA and clinical tests for upper extremity function in 20 patients with stroke. The CMSA for the arm was used to calculate the accuracy in tracking with the hand. The inter-class correlation coefficients for lap time, geometric trajectory error, trajectory error integrated over time and the marker trajectory error integrated over time were 0.45 (NS)-0.91 (P<0.01) in healthy participants and 0.62 (P<0.05)-0.90 (P<0.01) in patients with stroke. The trajectory error integrated over time and the geometric errors of the affected arm in stroke patients were negatively correlated with the Brunnstrom stage and the simple test for evaluating hand function. The marker trajectory error integrated over time in stroke patients was negatively correlated with the simple test for evaluating hand function. These results suggest that the CMSA for the arm is useful for quantitatively evaluating delicate visuo-motor skills of the arm.