['Recent trials suggest a link between neuropsychological function, atopy and allergic disease particularly in early childhood; however the nature of this association remains unclear.', 'To investigate the relationship between early allergic disease and sensitisation at 12 months of age and neurodevelopmental outcomes at 18 months.', 'Linear or binary logistic regression analysis was used to determine whether allergic diseases or sensitization at 12 months of age was a significant predictor of neurodevelopmental test scores at the 18 months.', 'Infants with a maternal history of allergic disease (n=324).', 'Allergic outcomes at 12 months of age included allergen sensitisation, eczema, IgE-mediated and food allergy, and neurodevelopmental outcomes at 18 included the Bayley Scales of Infant Toddler Development III Edition, the Achenbach Child Behaviour Checklist and the Macarthur Scales of Infant Toddler Development.', 'Children with any diagnosed allergic disease at 12 months had evidence of reduced motor scores (p=.016), and this was most apparent for a diagnosis of eczema (p=.007). Non-IgE mediated food allergy was significantly positively associated with problem Internalising Behaviours (p=.010), along with a trend for effects on the Social-Emotional composite score for IgE-Mediated food allergies (p=.052). Allergic sensitisation was not independently associated with any effects on neurodevelopmental outcomes.'] Is allergic disease in the first year of life associated with differences in subsequent neurodevelopment and behaviour?