As stress is hypothesised to influence dietary behaviour, the relationship between perceived stress and diet quality in European adolescents was investigated. Within the Healthy Lifestyle in Europe by Nutrition in Adolescence study, adolescents (n 704, aged 12–17 years) from schools in five European cities (Ghent, Stockholm, Zaragoza, Athens and Vienna) completed a 2 d 24 h dietary recall assessment and an Adolescent Stress Questionnaire. Measurements and information were taken on height, weight, pubertal stage, parental education level, the level of moderate-to-vigorous physical activity (MVPA) and sleep duration. The Diet Quality Index for Adolescents (DQI-A) was calculated from the dietary data, which comprised three components reflecting dietary diversity, quality and equilibrium. Hierarchical linear models were performed to investigate the relationship between the adolescents' level of perceived stress and the DQI-A and its components, adjusting for relevant covariates (age, BMI z-score, pubertal stage and parental education). These models were additionally adjusted for MVPA or sleep duration. In both boys and girls, perceived stress was a significant independent negative predictor for their overall DQI-A. This inverse relationship was observed for all dietary components, except for dietary diversity in boys, and it was unaltered when additionally adjusted for MVPA or sleep duration. The observed inverse relationship between stress and diet quality within these European adolescents supports the hypothesis that stress influences dietary behaviour, thus emphasising the need for preventive stress-coping strategies for adolescents.