Bangladesh recently experienced a COVID-19 second wave, resulting in the highest number of new cases and deaths in a single day. This study aims to identify the challenges for COVID-19 preventive practices and risk communications and associated factors among Bangladeshi adults. A cross-sectional survey was conducted between December 2020 and January 2021 involving 1382 Bangladeshi adults (aged ≥ 18-years) in randomly selected urban and rural areas from all eight divisions in Bangladesh. Descriptive data analysis was conducted to highlight the challenges for preventive practices and risk communications for COVID-19. Multiple logistic regression analysis was used to determine the sociodemographic groups vulnerable to these challenges. Lack of availability of protective equipment (44.4%), crowded living situations/workspaces (36.8%), inadequate information on the proper use of protective measures (21.9%), inadequate handwashing and sanitation facilities (17.6%), and negative influences on family/friends (17.4%) were identified as barriers to COVID-19 preventive practices. It was also found that males (OR = 1.3, 95% CI = 1.01, 1.7), rural residents (OR = 1.5, 95% CI = 1.2, 2), respondents with a low level of education: no schooling vs. ≥higher secondary (OR = 3.5, 95% CI = 2.3, 5.2), primary vs. ≥higher secondary (OR = 2.5, 95% CI = 1.7, 3.8), respondents engaged in agricultural (OR = 1.7, 95% CI = 1.2, 2.4), laboring (OR = 3.2, 95% CI = 2, 5), and domestic works (OR = 1.6, 95% CI = 1.07, 2.5), and people with disabilities (OR = 1.7, 95% CI = 1.1, 2.6) were all likely to have difficulty in practicing effective COVID-19 protective behaviors. Respondents’ education and occupation were significant predictors of inadequate understanding of COVID-19 risk communications and was identified as a problem among 17.4% of the respondents. A substantial percentage of Bangladeshi adults have difficulty practising COVID-19 protective behaviours and have poor comprehension of risk communications, particularly in rural areas and among those with low education. This research can aid policymakers in developing tailored COVID-19 risk communications and mitigation strategies to help prevent future waves of the pandemic.