The production and consumption of plastic bottled water have several negative environmental impacts worldwide. The EU countries have adopted strategies and programs to reduce single-use plastics (e.g. PET bottles). A critical aspect of designing effective policies is understanding consumer behaviour. To identify barriers and motivations for consuming tap and bottled water, we conducted a questionnaire survey among 3,411 respondents in the Czech Republic in 2022. The methods used include estimation using the Generalized Ordered Logit. The results reveal that young people appear to be moderate consumers of bottled water and heavy consumers of tap water. Bottled water consumption was more likely to be lower among people with higher education, while tap water consumption was lower among people with lower incomes. The factors that appear to have the most significant influence on bottled and tap water consumption are taste perception, health concerns and habit. Health concerns about tap water and the unpleasant taste of tap water influence higher consumption of bottled water and vice versa. People with a strong habit of drinking tap water are less likely to consume bottled water. The constructs from the Theory of Planned Behavior were statistically significant. The results can guide decision-makers by promoting the availability of tap water in public places in conjunction with a campaign targeting taste perception and health and promoting the habit of drinking tap water.