Assessment of suffering is extremely important in dying end-stage dementia patients (ESDP). We have developed and examined the reliability and validity of the (MSSE), in 103 consecutive bedridden ESDP. Main outcome measures included inter-observer reliability and concurrent validity. Reliability of the MSSE questionnaire was satisfactory, with Cronbach α values of 0.735 and 0.718 for the two physicians (Ph-1, Ph-2), respectively. The κ agreement coefficient was 0.791. There was a high agreement for seven items (κ 0.882–0.972) and a substantial agreement for the other three items (κ 0.621–0.682) of the MSSE. MSSE was validated versus the comfort assessment in dying with dementia (CAD-EOLD) scale and resulted in a significant Pearson correlation (r = −0.796, P < 0.001). We conclude that the MSSE scale is a reliable and valid clinical tool, recommended for evaluating the severity of the patient’s condition and the level of suffering of ESDP. Use of MSSE may improve medical management and facilitate communication between patients and caregivers. © 2003 Elsevier Ireland Ltd. All rights reserved. Keywords: Alzheimer; Dementia; End-of-life care; Hospice; Suffering E-mail address: email@example.com (B.Z. Aminoff).