Background In the first months of 2020, the SARS-CoV-2 virus spread all over the world and numerous measures were adopted that had a strong impact on both personal and public life. This contribution explores changes in alcohol and tobacco use during the first months of the COVID-19 pandemic in Slovenia. Methods Self-reported changes in alcohol and tobacco use during the first few months of the Covid-19 pandemic were recorded in 495 Slovenian adults, as part of the European Alcohol Use and COVID-19 survey. Results About half of the Slovenian sample indicated that the frequency of drinking occasions did not change in the months after the pandemic’s outbreak, while the remainder stated either a decrease (26.0%) or an increase (24.2%). 23.1% reported a decrease and 17.3% an increase in the quantity of alcohol consumed per occasion. Respondents who reported that their overall alcohol consumption decreased were more likely to be male than female and more likely to be younger than middle-aged. Those who reported experiencing at least a substantial level of distress due to financial loss were at a four-times increased risk of reporting an increase in their alcohol consumption compared to individuals who reported no or only some financial distress. Of the 120 people reporting the use of tobacco, almost half indicated an increase in tobacco consumption within the previous month, and about 20% reported a decrease in use. The differences in the results between Slovenia and other European countries are small and the overall pattern suggests that the situation in Slovenia was comparable to other European countries. Conclusion As this pandemic continues to evolve, further monitoring is needed to identify the long-term effects of alcohol and tobacco use on public health in relation to the management of COVID-19.