The purpose of this study was to examine the condition and functional properties, as well as adjustment and replacement needs, of 288 complete dentures worn by 144 inhabitants of Helsinki over 75 years old. Five different criteria to evaluate the need for replacement were used: (I) criteria based on Oral Health Surveys-Basic Methods (WHO, 1987); (II) criteria based only on the clinical data collected during the examination; (III) criteria based only on examiners' subjective opinion of the condition of the dentures; (IV) criteria based on clinical data as well as examiners' experience and consultation with the patient; (V) criteria based only on patients' subjective opinion. Depending on the evaluation method used, 10-84% of the dentures were judged to be in need of replacement. Strict objective evaluation methods produced the highest figures for replacement need, and method (I, WHO, 1987) the lowest. The most justifiable replacement percentage (26%) was achieved when the dentist assessed treatment need together with the patient. This study documents the multiple subjective and objective difficulties related to the wearing of complete dentures. The study also highlights the well-recognized importance of regular annual reexaminations for those wearing complete dentures and the assessment of need for adjustment of the dentures. It also demonstrates that successful treatment decisions cannot be made solely on the basis of clinical examination or a dentist's subjective opinion, but should be formulated in close consultation with the patient.