In this study, we found the sensitivity and specificity of family history data given by essential tremor (ET) patients to be 43.3% and 94.4%. Compared to relatives with less severe tremor (tremor score <24), those with more severe tremor (tremor score 24) were more likely to be identified by the ET probands (8/8 vs. 5/22, p=0.001, chi2 14.3). Our study suggests that family history information reported by ET patients was inaccurate, and poorly validated. Clinical and genetic studies in ET should take the limitation of family history data into consideration.