Access to safe water remains a critical challenge in developing countries, including Lao PDR, where reliance on untreated water and microbial contamination persists. This study evaluates a capacity-building teacher program on water quality education at teachers training college in Salavan Province, Lao PDR. The program consisted of a volunteer-led training followed by teacher-led instruction. Teachers' understanding, self-efficacy, motivation, and dissemination intention were assessed using a five-point Likert-scale questionnaire, and statistical analyses were conducted. Results showed high levels of understanding, self-efficacy, and motivation in both sessions, with no significant differences. Understanding significantly influenced self-efficacy, while only understanding remained a significant factor of motivation in multivariate analysis. All three factors were positively associated with knowledge dissemination, with motivation showing the strongest effect. Key challenges included lack of equipment and time constraints, which may limit the translation of knowledge into practice. These findings highlight the importance of integrating knowledge, self-efficacy, and motivation in capacity-building programs to support sustainable and teacher-led water quality education in low-resource settings.