Equilibrium is maintained by visual, proprioceptive and vestibular afferent influx, central coordination and motor efferents. Eleven male abstinent chronic alcoholic volunteers aged 44-65 years (mean 57 years) were investigated by randomized perturbed posturography. They had all been long time heavy drinkers. Ocular smooth pursuit and visual suppression of the vestibulo-ocular reflex showed abnormalities in a previous study, but they had no signs or symptoms of polyneuropathy. The current study demonstrated larger (but generally not significantly so) sway areas, and in all tests on the randomly moving support surface the sway velocities were significantly larger than in the controls. It is concluded that randomized perturbed posturography is valuable in dysequilibrium assessment in chronic alcoholics.