Introduction: Aproximately 30% to 50% of annual antimicrobial prescriptions are inappropriate or unnecessary, enhancing the development of bacterial resistance. It has been proposed that the responsible use of antimicrobials in undergraduate programs be emphasized. However, teachers usually do not manage effective strategies for this purpose. Aims: 1. Develop an instructional design, guided by the cognitive load theory, of a teaching and learning module to promote responsible use of antimicrobials 2. Evaluate the educational impact of the module on third-year Dental students. Methods: Action research and mixed methodology in four phases. i. Identification of learning needs and outcomes; ii. Instructional design guided by cognitive load theory; iii. Module implementation; iv. Educational impact on students was evaluated using satisfaction surveys, self-reports of learning outcomes achievement and a pre-post knowledge test. Descriptive and analytical statistical analysis (Wilcoxon test) and qualitative content analysis were used. Results: The antimicrobial module was designed in Canvas (LMS), allocating protected time for study and a classroom session. The educational impact was evaluated in 48 students. The satisfaction survey reported positive results on their 10 items (minimum 81.3%). The results of the self-reports of achievement of 7 learning outcomes and the pre-post test of 18 questions were statistically significant (p< 0.001). Conclusions: The design of this module could serve as a guide to promote the responsible use of antimicrobials while achieving greater satisfaction with students' experience and learning outcomes.