OBJECTIVE We examined the influence of head-tilting on stabilometry, which is similar to positional nystagmus in a sitting position. METHODS The subjects were 35 healthy individuals and 11 patients with unilateral vestibular disorder. We compared parameters measured in an upright position and those with left head-tilt or right head-tilt. We used Wilcoxon's signed ranks test for statistical analysis. RESULTS In the group of healthy adults, the Enveloped area with left head-tilt and right head-tilt increased significantly compared to that in the upright position (P=0.0111). The parameters that decreased significantly were Locus length per unit area (P=0.0007). The center of gravity on the Y-axis shifted backward significantly (P<0.0001). In the group of unilateral vestibular disorder, there were no parameters that showed significant difference CONCLUSIONS One could argue that a combination of displacement of the body itself, influence of proprioceptive sensation, and influence of otolith affects the output of stabilometry. It would be possible to develop this test if the first and the second are excluded.