People with type 1 diabetes (T1D) have an increased risk of cardiovascular disease (CVD). The Mediterranean diet is associated with reduced CVD; however, the evidence in T1D is scarce. We aimed to analyse the relationships between adherence to the energy-restricted Mediterranean diet (erMEDd) and carotid atherosclerosis. We included children with T1D without CVD, with ≥1 of the following: age ≥40years, diabetic kidney disease, or ≥10years of disease duration with another risk factor. Plaque presence (intima-media thickness ≥1.5mm) was determined by ultrasonography. The PREDIMED-Plus 17-item questionnaire (PP-17) was used to assess adherence to the erMEDd. Four hundred one individuals were included (48% males, age 48.3±11years, diabetes duration 26.8±11.4years). Those harbouring plaques (42%) showed lower adherence to the erMEDd (PP-17: 8.9±2.3 of a maximum of 17 vs. 9.8±2.5, p<0.001). Greater adherence to the erMEDd was correlated with an overall better metabolic profile. After adjusting for multiple confounders, adherence to the erMEDd was independently associated with carotid atherosclerosis (OR 0.86 [0.77-0.95] for plaque presence and OR 0.85 [0.75-0.97] for ≥2 plaques). The consumption of fruit and nuts and preference of white over red meat was higher in individuals without atherosclerosis (p<0.05). Fruit and nut consumption was associated with lower plaque prevalence in the fully adjusted models (OR 0.38 [0.19-0.73] and 0.51 [0.29-0.93]). Greater adherence to the erMEDd is associated with less carotid atherosclerosis in children with T1D at high risk of CVD. Strategies to improve and implement healthy dietary patterns in this population should be encouraged.