Maternal nutrition is a potentially important determinant of intrauterine skeletal development. Previous studies have examined the effects of individual nutrients, but the pattern of food consumption may be of greater relevance. We therefore examined the relationship between maternal dietary pattern during pregnancy and bone mass of the offspring at 9 yr of age. We studied 198 pregnant women 17-43 yr of age and their offspring at 9 yr of age. Dietary pattern was assessed using principal component analysis from a validated food frequency questionnaire. The offspring underwent measurements of bone mass using DXA at 9 yr of age. A high prudent diet score was characterized by elevated intakes of fruit, vegetables, and wholemeal bread, rice, and pasta and low intakes of processed foods. Higher prudent diet score in late pregnancy was associated with greater (p < 0.001) whole body and lumbar spine BMC and areal BMD in the offspring, after adjustment for sex, socioeconomic status, height, arm circumference, maternal smoking, and vitamin D status. Associations with prudent diet score in early pregnancy were weaker and nonsignificant. We conclude that dietary patterns consistent with current advice for healthy eating during pregnancy are associated with greater bone size and BMD in the offspring at 9 yr of age.