We assessed multimodal evoked potentials (EPs) in 13 children with newly diagnosed neurologically symptomatic Wilson's disease (WD) and in their first degree symptom-free relatives, consisting of seven presymptomatic and 15 asymptomatic siblings and 22 asymptomatic parents. EP abnormalities of at least one modality and one side stimulation were observed in 38.5% of patients, 42.9% of presymptomatic siblings, 21.4% of asymptomatic siblings and 18.2% of parents. Patients tended to have more prolonged central latencies of EPs. However, the left I-V interpeak brainstem auditory EP latency difference was the only one to reach at the statistical significance (P = 0.001). Abnormal VEP P100 latency was detected more frequently in presymptomatic siblings than those in asymptomatic ones (42.9% vs 7.1%, P = 0.049). In all relatives, other diagnostic tests including electroencephalography, electromyography and head magnetic resonance imaging (MRI) for subclinical nervous system involvement and Kayser-Fleischer rings examination yielded normal results.