The article presents findings from the first comparative European survey on health literacy, conducted in eight countries (Austria, Bulgaria, Germany, Greece, Ireland, the Netherlands, Poland, and Spain). The survey, known as the European Health Literacy Survey (HLS-EU), aimed to measure health literacy levels and identify vulnerable groups with limited health literacy. Key findings include: 1. **Health Literacy Levels**: At least 12% of respondents showed insufficient health literacy, and nearly 47% had limited health literacy (insufficient or problematic). The distribution of these levels varied significantly across countries, ranging from 29% to 62%. 2. **Vulnerable Groups**: Subgroups defined by financial deprivation, low social status, low education, and old age had higher proportions of people with limited health literacy, indicating a social gradient. 3. **Social Gradient**: Financial deprivation was the strongest predictor of low health literacy, followed by social status, education, age, and gender. This gradient was confirmed by both bivariate correlations and multivariate linear regression models. 4. **Policy Implications**: Limited health literacy represents a significant challenge for health policies and practices across Europe. The social gradient in health literacy must be considered when developing public health strategies to improve health equity. The study highlights the need for targeted interventions to address health literacy deficits, particularly in vulnerable populations, and emphasizes the importance of involving these groups in health promotion efforts. The HLS-EU data provides a valuable resource for comparing health literacy levels within and between EU member states, supporting informed decision-making in health policy and practice.The article presents findings from the first comparative European survey on health literacy, conducted in eight countries (Austria, Bulgaria, Germany, Greece, Ireland, the Netherlands, Poland, and Spain). The survey, known as the European Health Literacy Survey (HLS-EU), aimed to measure health literacy levels and identify vulnerable groups with limited health literacy. Key findings include: 1. **Health Literacy Levels**: At least 12% of respondents showed insufficient health literacy, and nearly 47% had limited health literacy (insufficient or problematic). The distribution of these levels varied significantly across countries, ranging from 29% to 62%. 2. **Vulnerable Groups**: Subgroups defined by financial deprivation, low social status, low education, and old age had higher proportions of people with limited health literacy, indicating a social gradient. 3. **Social Gradient**: Financial deprivation was the strongest predictor of low health literacy, followed by social status, education, age, and gender. This gradient was confirmed by both bivariate correlations and multivariate linear regression models. 4. **Policy Implications**: Limited health literacy represents a significant challenge for health policies and practices across Europe. The social gradient in health literacy must be considered when developing public health strategies to improve health equity. The study highlights the need for targeted interventions to address health literacy deficits, particularly in vulnerable populations, and emphasizes the importance of involving these groups in health promotion efforts. The HLS-EU data provides a valuable resource for comparing health literacy levels within and between EU member states, supporting informed decision-making in health policy and practice.