Objective: To construct a needs assessment instrument for older people using a standardized terminology (International classification of functioning, disability, and health [ICF]) and assess its psychometrical properties. Method: An instrument was developed comprising questions to older people regarding their perceived care needs. The instrument's reliability, validity, and utility were tested. Forty-one social workers and 251 older people participated. Results: The questions were sufficiently unambiguous (inter-rater reliability, intraclass correlation = 0.60-0.80); measured a person's care and service needs to a satisfactory extent (criteria validity, agreement between social workers' and older people's assessments = 72-94%); both social workers and older people considered the questions useful; and the needs of older people were documented in social records to a greater extent when the instrument was used. Conclusion: The psychometric properties of the instrument support its use by social workers to gain relevant information on elder care needs.