Background and aims: Food processing has been indicated as a factor capable of negatively affecting the global food system, including the profile of consumers’ diets. The objectives of the present study were to provide a description of the consumption of ultra-processed foods (UPFs) in the large population of children, adolescents and adults from eight European countries participating to the I.Family study, and to investigate the association between UPFs intake and nutritional quality of the diet. Methods and results: Dietary intake was assessed using a 24-h dietary recall. The quality of the diet was evaluated by the Healthy Dietary Adherence Score (HDAS) using an FFQ. UPFs were classified according to the NOVA classification. Almost half of the daily energy intake of the 7073 participants came from UPFs, and this trend decreased progressively with age. UPFs contributed more than 50 % of the daily intake of total and saturated fat, carbohydrates and about 70 % of sugars intake in children and adolescents. No differences in UPFs consumption were found according to the educational and socio-economic status of the population. Energy intake increased across the quintiles of UPFs intake, while HDAS decreased. The frequency of consumption of fruit and vegetable, fish, and fibre rich foods was low in the fifth quintile of UPFs intake, both in adolescents and in adults. The consumption of foods rich in calories and low in nutritional content, operationally defined as “junk food”, was significantly higher in the fifth quintile. Conclusions: In the population of the European I.Family study, UPFs contributed a large proportion of the daily energy intake, especially in children and adolescents. Higher consumption of UPFs was associated with a lower quality of the diet. Registration number for clinical trials: ISRCTN62310987.