studies have shown that milk and dairy consumption in adulthood have beneficial effects on health. we examined the impact of childhood and adult diet on physical performance at age 63-86 years. The Boyd Orr cohort (n=405) is a 65-year prospective study of children who took part in a 1930's survey; the Caerphilly Prospective Study (CaPS; n=1,195) provides data from mid-life to old age. We hypothesised that higher intakes of childhood and adult milk, calcium, protein, fat and energy would be associated with a better performance. in fully adjusted models, a standard deviation (SD) increase in natural log-transformed childhood milk intake was associated with 5% faster walking times from the get-up and go test in Boyd Orr (95% CI: 1to 9) and 25% lower odds of poor balance (OR: 0.75; 0.55to 1.02). Childhood calcium intake was positively associated with walking times (4% faster per SD; 0to 8) and a higher protein intake was associated with lower odds of poor balance (OR: 0.71; 0.54to 0.92). In adulthood, protein intake was positively associated with walking times (2% faster per SD; 1to 3; Boyd Orr and CaPS pooled data). this is the first study to show positive associations of childhood milk intake with physical performance in old age.