With the aim of verifying the suitability of the CES-D scale for use in long-term care institutions for older adults, the CES-D questionnaire was used to collect patient-reported assessments, and two well-known psychometric instruments – the Hospital Anxiety and Depression Scale and the Barthel Index of Abilities of Daily Living – were used to collect nurse-reported assessments, based on observations of patients’ behaviours. With regard to possible frequent cases of cognitive impairment and/or insufficient motivation to give sensible responses to CES-D (...) questions, the patient-reported responses were collected from patients during one-on-one sessions with a nurse. The reliability, concurrent validity, and the trustworthiness of the obtained data were supported with proper values of the Cronbach’s alpha coefficient, 0.70 < alpha < 0.85, with significant correlation between CES-D and HADS-Depression, R = 0.50, p < 0.001, and with significant correlation between scores of particular CES-D items vs. final CES-D evaluations of depression, proved by significance p < 0.001 for 18 of 20 CES-D items. These findings supported the effectiveness of the one-on-one session methodology in questionnaire surveys for older adults. The postulation that cases of self-reported depression included somewhat different information about the patient than nurse-reported depression concerning the same patient was supported with the evidence that, in spite of the significant correlation between the Barthel Index and HADS-Depression, R = −0.17, p = 0.016, and in spite of the significant correlation between CES-D and HADS-Depression, the correlation between the Barthel Index and CES-D, equal to R = −0.08 was insignificant at p = 0.244. The findings of this study, considered jointly, support the valuableness of the CES-D scale for use in one-on-one surveys for older adults. (shrink)