Background: Height and BMI are risk factors for several types of cancer and may be related to circulating concentrations of insulin-like growth factor-I (IGF-I), a peptide associated with increased cancer risk. Aim: To assess the associations between height, BMI and serum concentrations of IGF-I and IGF binding protein (IGFBP)-1, -2 and -3. Subjects and methods: This cross-sectional analysis included 1142 men and 3589 women aged 32-77 years from the multi-centre study, the European Prospective Investigation of Cancer and Nutrition (EPIC). Results: In men, there was a positive association between height and IGF-I; each 10 cm increment in height was associated with an increase in IGF-I concentrations of 4.3% (95% confidence interval (CI): 1.3-7.5%, p for trend = 0.005), but this association was not statistically significant for women (0.9%, 95% CI: -0.7 to 2.6%, p for trend = 0.264). In both men and women, the association between IGF-I and BMI was non-linear and those with a BMI of 26-27 kg/m2 had the highest IGF-I concentration. BMI was strongly inversely related to concentrations of IGFBP-1 and IGFBP-2 in men and in women (p for trend for all < 0.001). Conclusion: Height and BMI are associated with IGF-I and its binding proteins, which may be mechanisms through which body size contributes to increased risk of several cancers.