Evaluation is a critical component of any conservation education strategy, but especially important in highly threatened ecosystems where no formal incentives for conservation are available. We assessed the effectiveness of biodiversity education workshops in influencing knowledge, beliefs, personal norms and conservation behaviors among Chilean winegrowers. We used a switching replication design with pre, post and follow-up tests to measure the impact of two workshop formats on 164 participants at four wineries. Environmental knowledge increased after workshops and persisted over time. Perceived ability to reduce threats to biodiversity also increased, but only significantly at one winery. No differences were found between the conventional workshop, more focused on technology transfer, and the participatory format. The limited effect of the workshops on variables influencing behavior change suggests modifications are needed. The value-belief-norm theory provided insights on how to improve these conservation education workshops, such as developing messages targeting specific consequences of environmental problems.