Ensuring high compliance with age restrictions on tobacco/nicotine and alcohol sales is essential to prevent access and use among youth. Mystery shopping is a way to check compliance with age restrictions. The aim of this survey was to compare the status of and experiences with mystery shopping of tobacco/nicotine and alcohol products in European countries. We conducted a cross-sectional survey to explore the use and characteristics of mystery shopping practices. The information was obtained from the identified contacts in 30 European countries. Mystery shopping was conducted in 20 out of 30 countries, mostly for both groups of products. In around two thirds of countries with mystery shopping, it was conducted regularly and on the national level, including different subcategories of tobacco/nicotine products (including new tobacco/nicotine products) and alcoholic beverages. All countries had conducted mystery shopping at physical points of sale, but rarely online. Methods of mystery shopping practices varied among countries. In most countries, the mystery shoppers were minors and the financial and human resources were not always ensured, raising concerns regarding the ethical aspects and continuation of mystery shopping use. Mystery shopping practices vary among European countries. Developing standardized, sustainable, and ethically sound protocols for effective mystery shopping would facilitate use of mystery shopping across countries, support comparability of results, and promote sharing of best practices. Future efforts should include online sales channels, which are increasingly used by youth.