Background/Objectives:Evidence supporting the association between skipping breakfast and children's body mass index (BMI) has been widely reported, and some consideration has been given to children aged 2-5 years. However, no evidence has considered an association between children skipping breakfast and mother's BMI. This study therefore investigated associations between skipping breakfast, child's BMI and mother's BMI in a large cohort of Australian children.Subjects/Methods:Data were drawn from wave 2 (2-3 years, n=4601) and wave 3 (4-5 years, n=4381) of the Longitudinal Study of Australian Children. The primary outcome was skipping breakfast. Child's and mother's BMI was assessed by trained professionals.Results:Girls at 4-5 years were significantly more likely to skip breakfast compared with boys (56.9% versus 43.1%; P=0.031). In cross-sectional data analysis, obese boys at 2-3 years (odds ratio (OR) 2.38; P=0.039) and at 4-5 years (OR 2.32; P=0.046), and also obese girls at 4-5 years (OR 2.26; P=0.018), were more likely to skip breakfast. Skipping breakfast was positively associated with boys at 2-3 years (OR 2.04; P=0.042) whose mothers were overweight and with girls at 4-5 years (OR 2.60; P=0.001) whose mothers were obese. In longitudinal cross-lagged analysis, boys at 2-3 years whose mothers were obese were more likely to skip breakfast 2 years later at age 4-5 years (OR 2.36; P=0.045).Conclusions:Skipping breakfast was associated with higher BMI in children and mothers. Future interventions should target obese mothers to promote breakfast intake among children. The interventions may involve changes to dietary and lifestyle habits and provision of education on the benefits of breakfast intake.