In 2005 a nationwide monitoring scheme for butterflies (and diurnal moths) was launched in Germany. Coordinated by the Helmholtz Centre for Environmental Research—UFZ, it started as an integral part of the public relations campaign "Abenteuer Schmetterling" (Adventure Butterfly) with German public television and an environmental NGO as partners. The core objectives of the monitoring scheme are (a) to provide a central element for the analysis of biodiversity and (b) to investigate and develop the role of butterflies as indicators for the state of biodiversity. Both are aims at a regional, national, and European scale. After three years of monitoring (2005-2007), first results and experiences are presented. We show that the use of multiple media (TV, internet, community-level activities) yielded high responsiveness from the public and high recruitment of volunteers. We further show that the quality of data is likely to qualify for scientific analyses of abundances and phenology and therefore possibly for the recognition of long-term trends. Main lessons learned for the successful establishment of a volunteer-based monitoring scheme are that (a) an institution that hosts such a project should be able to provide long-term basic financial and personnel resources; (b) the media can play a vital role in activating a minimum number of volunteers required to start a monitoring project; and (c) the motivation of recorders is the key for success. Therefore permanent coordination, support, motivation activities, continuous contacts with the volunteers, and continuous recruitment of new recorders are all essential to ensure regular data entry and the overall success of such a project.