Background/objectives: Picky eating may be associated with higher risk of being underweight and poor growth over time or conversely, being overweight. Our aim was to investigate if children identified as picky eaters showed differences in height, weight and body composition from their non-picky peers. Subjects/methods: Picky eaters were identified in the Avon Longitudinal Study of Parents and Children cohort at 3 years of age. Height and weight were measured on seven occasions (age 7–17 years). Body composition was measured on five occasions by dual-energy x-ray absorptiometry (age 9–17 years). Participants were classified as thin/normal/overweight or obese at each age point using body mass index (BMI) classifications. Data were analysed with adjusted multiple regression analysis and mixed-design repeated measures ANOVA. Results: There was a main effect of being a picky child on height and weight (and on BMI and lean mass index (LMI) in boys) (lower in the picky children, all p ≤ 0.044), but not on percentage body fat or fat mass index (and not on BMI and LMI in girls) (all p > 0.2). The mean heights, weights and BMIs of picky eaters were consistently above the 50th centiles of reference growth charts. More than two-thirds of picky eaters were not thin at any age point. However, being a picky eater was predictive of being thin at a few age points. Conclusions: The growth trajectories of children who were picky eaters were reassuring. The prevalence of thinness amongst some picky eaters is notable, suggesting that some children may need specific early identification, intervention and growth surveillance.