The aim of the present study was to examine the associations between the maternal intake of fatty acids during pregnancy and the risk of preclinical and clinical type 1 diabetes in the offspring. The study included 4887 children with human leucocyte antigen (HLA)-conferred type 1 diabetes susceptibility born during the years 1997-2004 from the Finnish Type 1 Diabetes Prediction and Prevention Study. Maternal diet was assessed with a validated FFQ. The offspring were observed at 3-to 12-month intervals for the appearance of type 1 diabetes-associated autoantibodies and development of clinical type 1 diabetes (average follow-up period: 4.6 years (range 0.5-11.5 years)). Altogether, 240 children developed preclinical type 1 diabetes and 112 children developed clinical type 1 diabetes. Piecewise linear log-hazard survival model and Cox proportional-hazards regression were used for statistical analyses. The maternal intake of palmitic acid (hazard ratio (HR) 0.82, 95% CI 0.67, 0.99) and high consumption of cheese during pregnancy (highest quarter v. intermediate half HR 0.52, 95% CI 0.31, 0.87) were associated with a decreased risk of clinical type 1 diabetes. The consumption of sour milk products (HR 1.14, 95% CI 1.02, 1.28), intake of protein from sour milk (HR 1.15, 95% CI 1.02, 1.29) and intake of fat from fresh milk (HR 1.43, 95% CI 1.04, 1.96) were associated with an increased risk of preclinical type 1 diabetes, and the intake of low-fat margarines (HR 0.67, 95% CI 0.49, 0.92) was associated with a decreased risk. No conclusive associations between maternal fatty acid intake or food consumption during pregnancy and the development of type 1 diabetes in the offspring were detected.