Abstract. With regard to water scarcity in many parts of the world as well as the energy used for water heating in countries where water is abundant, the use of ICT for providing feedback and promoting (hot) water conservation has gained increasing attention. In a pilot project, a feedback device for showers has been developed which is able to show consumption data immediately as well as to transmit it to digital devices. The usage of this feedback device has been tested in a pilot test within two samples in Alicante, Spain, and in St. Albans, UK, for about 12 months, including different elements (such as feedback about the own consumption as well as comparative feedback). Besides consumption data, psychological factors (such as problem awareness, personal and social norms, perceived response efficacy) which determine consumption behavior were assessed via a questionnaire before and at the end of the pilot test. Effects of the intervention with regard to changes of the psychological variables, shower behavior, as well as water and energy consumption will be presented and discussed together with implications for the further development and application of similar feedback interventions.