Both the Camberwell Family Interview (CFI) and the Five-Minute Speech Sample (FMSS) have been used to define expressed emotion (EE), but the validity of the FMSS relative to the CFI in mood disorders has not been evaluated. In our study, the FMSS and the CFI were performed on the same day in close family members of inpatients with mood disorders within 2 weeks after their admission. The ratings obtained from the CFI were then used to estimate the validity of the FMSS, which was defined by sensitivity and specificity on the basis of the overall evaluation of EE. Validity was also assessed by including borderline ratings of 'low EE' in the category of 'high EE.' Based on the overall evaluation, sensitivity and specificity were 66.7 and 96.8%, respectively. When borderline low EE was included in high EE, the sensitivity and specificity were 100 and 90.3%, respectively. The validity of definitions of EE by the FMSS relative to the CFI was high in mood disorders. Evaluation of EE by the FMSS, which is clinically applicable to patients with mood disorders, is feasible. The validity of this approach is enhanced when families defined as 'borderline low EE' are included in the high-EE category.