Objective: To assess whether higher adherence to the traditional Mediterranean diet (MedDiet) was associated with lower consumption of ultra-processed foods (UPF) and lower free sugar intake. Design: Cross-sectional analysis of baseline information among participants in the SENDO project, a Spanish paediatric cohort. Dietary information was collected through a semi-quantitative FFQ. Food items were classified according to the NOVA classification. Adherence to the MedDiet was evaluated through the KIDMED index. Setting: Spain. Participants: Three hundred eight-six children (52 % boys) with a mean age of 5 center dot 3 years old (sd 1 center dot 0) were included in the analysis. Results: 74 center dot 4 % of the children had moderate adherence to the MedDiet (mean KIDMED score: 5 center dot 9 points; sd 1 center dot 7) and overall, 32 center dot 2 % of the total energy intake came from UPF. Each two additional points in the KIDMED score was associated with 3 center dot 1 % (95 % CI 2 center dot 1, 4 center dot 0) lower energy intake from UPF. Compared to those with low adherence to the MedDiet, children with medium and high adherence reported 5 center dot 0 % (95 % CI 2 center dot 2, 7 center dot 7) and 8 center dot 5 % (95 % CI 5 center dot 2, 11 center dot 9) lower energy intake from UPF, respectively. We also found that 71 center dot 6 % of the variability in free sugar intake was explained by the variability in UPF consumption. Conclusions: Adherence to the traditional MedDiet was inversely associated with energy intake from UPF. Furthermore, most of the variability in free sugar intake was explained by the variability of UPF consumption. Public health strategies are needed to strengthen the adherence to the MedDiet in pre-schoolers while regulating the production, marketing and advertising of UPF.