BACKGROUND AND OBJECTIVES: Until recently, attention and treatment strategies have focused mainly on patients in the early phases of Alzheimer’s disease (AD). The objectives of this study were to collect information on moderately severe and severe AD patients (Mini-mental State Examination score < 15) in terms of epidemiological, clinical and economic characteristics and disease change in the later stages of AD, and to compare this specific AD population over 6 months with those in the earlier stages. METHODS: This descriptive analysis recruited institutionalized patients and patients living within the community from the city of London and the South-East region of the U.K. Subgroup analyses at baseline and 6 months were performed using the study population from the London and South-East Region Alzheimer's Disease (LASER-AD) Study. Data from a range of clinical scales, a quality of life (QOL) scale and a resource-utilization questionnaire were analyzed. RESULTS: People with moderately severe or severe AD are a heterogeneous group with varying QOL, cognitive and functional disabilities, neuropsychological symptoms and relatively low health care resource consumption. This patient group continued to decline but progression of the disease was observed only in some domains. CONCLUSION: Even at the later stages of AD, patients show varying rates of decline. Improved knowledge about the characteristics and progression of the disease reveals that moderately severe and severe patients cannot be regarded as beyond help and have the potential to experience varying and even high levels of QoL.