ObjectivesTo evaluate the understanding, opinions and actions concerning COVID-19, referred to as knowledge, attitudes and practices (KAP), among rural adolescents in Bangladesh. Additionally, the study aimed to identify the determinants that may influence adolescents’ KAP.DesignAn interview-based cross-sectional study.SettingThe study area was the Thakurgaon district, which was located in the northwestern region of Bangladesh.ParticipantsA total of 266 rural adolescents were selected using a non-probability (convenience sampling) technique.Main outcome measuresSociodemographic characteristics, source of information, COVID-19-related KAP, and their associated factors.ResultsThe majority of the respondents were females and reported that mass media (eg, television channels and papers) was the main source of information to learn about COVID-19. The mean score for knowledge was 7.15±3, whereas the scores were 10.5±2.8, and 8.78±2.66 for attitude and practice, respectively. Among the adolescents, only 11% had adequate knowledge, a positive attitude (27%) and good practices (31%). The predictive factors related to adolescents' knowledge and attitude were their religion, educational level and family income. Adolescents who were from the Islamic religion and who had secondary education were more knowledgeable and encompassed more positive attitudes. Besides, poor KAP towards COVID-19 was significantly higher among the participants with the lowest family income (less than 10 000 BDT). Moreover, their knowledge was significantly associated with their attitudes and practices.ConclusionThe study found that adolescents in rural areas lacked sufficient knowledge of COVID-19 and engaged in unsatisfactory preventative behaviour. Therefore, the development of effective health education programmes that incorporate consideration of KAP-modifying factors is needed. In addition, the result would be helpful for other similar types of pandemics.