The sensitivity of the Mini Mental State Evaluation (MMSE) in severely impaired patients is reduced by a floor effect and limited score range. The Severe Impairment Battery (SIB) and Preliminary Neuropsychological Battery (BNP) may be valid alternatives. We studied a group of 37 severely compromised elderly inpatients to investigate the usefulness of these two test batteries as alternatives to the MMSE. Both proved reliable, but only the SIB had a wider distribution of results with respect to the MMSE in the lower score range. The BNP, that might be thought easier to perform being a simple verification task, could actually not be completed by the most compromised patients. The SIB seems better able than the MMSE to provide cognitive profile in the three diagnostic categories into which patients were subdivided (Psychogeriatric, Psychorganic, Mentally Retarded). We conclude that it may be useful to test patients with the SIB when they yield a MMSE score lower than 10–12 points.