BACKGROUND: The purpose of this study was to quantitatively assess the subclinical balance dysfunction in elderly people taking antiepileptic drugs. METHODS: We recruited sixty-three patients who were at least 50 years old, without complaint of dizziness or imbalance, and on a stable dose of carbamazepine, lamotrigine or levetiracetam. Their balance scores were compared with those of newly diagnosed untreated age- and sex-matched epilepsy patients (n=21). All the subjects underwent balance measurements that included an activities-specific balance confidence scale, quantitative caloric and rotational chair testing and posturography. The spectral frequency analysis of body sway while standing upright was also investigated. Sensory organization (SOT) and motor control tests were done by computerized dynamic posturography (CDP). RESULTS: The sway distance and area of center of pressure significantly increased in the patients treated with carbamazepine. Spectral frequency analysis of this group showed a significantly increased spectral power at low and middle frequencies on the antero-posterior (Y) plane and at low frequencies on the lateral (X) plane. CDP showed no significant differences in SOT results among the groups. However, motor control test revealed increased latencies and slowed adaptations in the carbamazepine group. CONCLUSIONS: These findings suggest that newer drugs such as lamotrigine or levetiracetam may induce less disequilibrium than carbamazepine in older people on monotherapy for epilepsy. The disturbance is likely related to slowed central postural reflexes.