The adoption of Circular Economy approaches in agriculture offers opportunities to transform agricultural waste into valuable resources. This study was conducted within the TANGO-Circular project, which implemented Rural Lab training activities in four European countries: Greece, Italy, Portugal, and Spain. A structured questionnaire was administered to participants involved in these activities. Overall, 197 questionnaires were collected, of which 195 valid responses were included in the final quantitative analysis. Respondents included farmers, technicians, students, and other actors connected to agricultural and sustainability-related contexts. The results indicate that, despite differences in sample composition across countries, no statistically significant differences were observed in awareness and interest toward Circular Economy practices within the analyzed sample. Conversely, statistically significant differences emerged in gender distribution, professional profile, and perceived barriers among countries. Overall, respondents exhibited a generally positive attitude toward agricultural waste valorization and a high level of interest in further training activities. However, key barriers were identified, including lack of technical knowledge, limited institutional support, lack of awareness, and high initial costs. These findings suggest that the adoption of Circular Economy practices in agriculture requires not only positive attitudes, but also targeted training, accessible support services, and institutional and logistical frameworks adapted to local contexts.