BACKGROUND: The consumption of non-alcoholic beer and other non-alcoholic and low-alcohol beverages has grown significantly in recent years. Due to a lack of suitable datasets, there have been few studies conducted on the forerunners of the non-alcoholic beer consumption trend. This study examined the associations of sociodemographic characteristics with non-alcoholic beer purchase, and of non-alcoholic beer purchases with regular beer purchases. METHODS: The data consisted of longitudinal individual purchases of non-alcoholic and regular beer from grocery stores in 2017 and 2018. The study participants were loyalty cardholders from the largest food retailer in Finland (n = 47,066). The level of education, household income and occupational status were analyzed as determinants of non-alcoholic beer purchase using logistic regression models. The changes in the regular and non-alcoholic beer purchases from 2017 to 2018 and the distributions of non-alcoholic beer purchase by regular beer purchase, by gender and by age were described. RESULTS: Between 2017 and 2018, the total volume of non-alcoholic beer purchases increased from 2.3% to 3.7% of the total volume of all beer purchases. Men and older people purchased non-alcoholic beer more often than women and younger people did. Non-alcoholic beer purchases were most common among the highly educated and high-income consumers. Non-alcoholic beer purchases were most prevalent in the groups with the highest volumes of regular beer purchase. CONCLUSIONS: Educated and affluent consumers have been the forerunners of non-alcoholic beer consumption in Finland. In order to promote the substitution of regular beer with non-alcoholic beer the shift towards lower-strength beverages should be facilitated across social strata.