This paper describes a multi-national study evaluating the perceived usefulness and perceived ease of use of Ambient Intelligence (AmI) applications in office environments. In a first step, existing usage scenarios were analyzed to identify characteristic functionalities and application domains. The identified core functionalities were integrated into a representative and coherent evaluation scenario, which was presented to a target user population in a questionnaire-based study. The results of the study indicate, that the participants regard the described Ambient Intelligence functionalities as rather useful and easy to use. Nevertheless, moderate overall ratings for both factors show, that the acceptance of AmI technologies is not as high as often argued.