The Ministry of Health of the Republic of Indonesia has developed a COVID-19 prevention poster for use in educational institutions . The poster was pretested to determine the reactions of individuals at educational institutions in Depok City in relation to various aspects of communication, such as attraction, comprehension, acceptability, self-involvement and persuasion . The research was descriptive and qualitative, and informants were selected by purposive sampling . The six research informants were teachers and students from a junior high school and a senior high school . Data were collected by using in-depth virtual interviews, and data were analysed using thematic analysis . According to our findings, both teachers and students found the information, images and words of the poster interesting, while the language and terms used were easily understood . In addition, the information was useful and appropriate to the situation and needs . However, titles should be more attractive and specific . In conclusion, according to the input from teachers and students, the COVID-19 prevention poster for educational institutions needs minor revisions . An additional recommendation was that the Indonesian Ministry of Health logo should be added to confirm the source and credibility of the poster.