Research is needed on environmental and sustainability education (ESE) programs implemented by public administrations. This study expands knowledge on ESE policy and instrument evaluation. Following the theory of change approach, semi-quantitative analysis of the evaluation questionnaire was used to examine the principles (organizational culture) of the Basque Country's School Agenda 21 (SA21) program. Questionnaire answer options identified only partly responded to theory of change objectives. Results emphasized the need to address weaknesses of the questionnaire and SA21 program, particularly future modifications related to higher family and society engagement, focus on attitudes and behaviors, and an integrated sustainability concept. Regarding organizational context, program evaluation can be improved if the program coordinator is not solely responsible for answering the questionnaire. Further, students should have a more active role in evaluation. Research conducted with and in public administrations can improve evaluation processes and the educational system by highlighting virtues and proposing specific improvements.