ABSTRACT: In adults, adherence to the Mediterranean diet has been inversely associated with cardiovascular risk, but the extent to which diet in pregnancy is associated with offspring adiposity is unclear. We aimed to investigate the association between adherence to Mediterranean diet in pregnancy and offspring cardiometabolic traits in two pregnancy cohorts.We studied 997 mother-child pairs from Project Viva in Massachusetts, USA, and 569 pairs from the Rhea study in Crete, Greece. We estimated adherence to the Mediterranean diet with an a priori defined score (MDS) of nine foods and nutrients (0 to 9). We measured child weight, height, waist circumference, skin-fold thicknesses, blood pressure, and blood levels of lipids, c-reactive protein and adipokines in mid-childhood (median 7.7?years) in Viva, and in early childhood (median 4.2?years) in Rhea. We calculated cohort-specific effects and pooled effects estimates with random-effects models for cohort and child age.In Project Viva, the mean (SD, standard deviation) MDS was 2.7 (1.6); in Rhea it was 3.8 (1.7). In the pooled analysis, for each 3-point increment in the MDS, offspring BMI z-score was lower by 0.14 units (95% CI, -0.15 to -0.13), waist circumference by 0.39?cm (95% CI, -0.64 to -0.14), and the sum of skin-fold thicknesses by 0.63?mm (95% CI, -0.98 to -0.28). We also observed lower offspring systolic (-1.03?mmHg; 95% CI, -1.65 to -0.42) and diastolic blood pressure (-0.57?mmHg; 95% CI, -0.98 to -0.16).Greater adherence to Mediterranean diet during pregnancy may protect against excess offspring cardiometabolic risk.