Abstract Background Introduction of vaccines against COVID-19 has not encountered expected acceptance. The uptake of COVID-19 vaccines in Western Balkans countries is lagging behind the European Union average. The aim of our study was to assess the intention to get vaccinated against COVID-19 in the population of unvaccinated adult citizens of five Western Balkans countries, and to explore factors that influence the vaccination intention. Methods Cross-sectional study was conducted in the period from July to October 2021. The questionnaire was shared through online social media. Intention to get vaccinated against COVID-19 was measured by a single item assessing the likelihood of getting vaccinated on a 5-points Likert scale. Linear regressions were conducted with socio-demographic characteristics, presence of chronic diseases and attitudes towards COVID-19 vaccination as independent factors. Results The largest proportion of unvaccinated respondents willing to get vaccinated in the future was observed in Montenegro and Albania (40.4% in each country), while in the Serbian sample, the willingness to get vaccinated was the lowest (22.6%). Socio-demographic characteristics were not significantly associated with the intention to get vaccinated against COVID-19 in most of the countries. In Albania, Bosnia and Herzegovina, North Macedonia and Serbia the strongest determinant of COVID-19 vaccination intention was the higher sense of social responsibility. Conclusions Vaccination interventions and campaigns aiming to improve the COVID-19 vaccine uptake should be focussed on specific set of factors in each country, appealing to social responsibility as most prevalent determinant of vaccination intention in Western Balkans.