The analyses of an international pilot study presented in this article focused on the development of a cross-nationally valid activities-of-daily-living (ADL) scale sensitive to therapeutic effects in patients with mild memory impairment and mild to moderately severe dementia. The present report, which is part of an ongoing international research project, describes field testing results for 141 informant-rated items. The comparability of samples investigated in research centers in the U.S.A., Germany, Russia, and Greece concerning cognitive decline was evaluated globally as well as psychometrically using the Global Deterioration Scale, the Short Cognitive Performance Test, and the Mini-Mental State Examination. In the participating countries, a composite ADL score discriminated well between different stages of cognitive impairment because of dementia. However, international differences between the applied measures were observed. A practical ADL scale showing therapeutic sensitivity and international utility, will be constructed from the 141 informant-rated items under investigation in this pilot work.