Maternal nutrition knowledge has frequently been identified as an important target for nutrition promotion interventions. The aim of the present study was to investigate whether maternal nutrition knowledge is more strongly associated with the mother's own diet or that of her child.

Cross-sectional multivariate linear regression with interactions analyses of survey data.

Socio-economically disadvantaged neighbourhoods in Victoria, Australia.

Five hundred and twenty-three mothers and their children who participated in the Resilience for Eating and Physical Activity Despite Inequality (READI) study, a cross-sectional survey study conducted in 2009 among women and their children residing in socio-economically disadvantaged neighbourhoods.

In adjusted models, for three (vegetable, chocolate/lollies and soft drink consumption) out of the seven dietary outcomes assessed, there was a significant association between maternal nutrition knowledge and maternal diet, whereas for the children's diets none of the seven outcomes were associated with maternal nutrition knowledge. Statistical comparison of regression coefficients showed no difference between the maternal nutrition knowledge–maternal diet association and the maternal nutrition knowledge–child diet association.

Promoting maternal nutrition knowledge may represent an important avenue for improving diet in mothers from socio-economically disadvantaged neighbourhoods, but more information is needed on how and when this knowledge is translated to benefits for their children's diet.