Height, weight, and body mass index (BMI) are partly heritable, known to be associated with chronic diseases, and are linked to circulating insulin-like growth factor I (IGF-I) concentrations. IGF-I concentrations are also partly heritable and thus genetic variation at IGF1 could influence height, weight, BMI and the risk of developing chronic diseases. Our objective was to examine the association of genetic variation at IGF1 with height, weight and BMI using a sample of premenopausal women. A family-based study design was used to investigate the association of three IGF1 CA repeat variants at 5' (5'CA), intron 2 (In2CA) and 3' (3'CA) with these anthropometric measures. We analyzed the data for 827 families of different sizes and configurations, which included 1520 premenopausal women. Nominally significant associations (P<or=0.05) were found for a rare 3' variant allele (3'CA-193) and BMI (P=0.05), and for the more common 3'CA-187 allele and weight (P=0.04). These associations did not remain significant when adjusted for multiple comparisons. Haplotype analysis did not support an association between these variants and anthropometric measures. This study does not support an association between IGF1 and these anthropometric measures. Study limitations, including sample size and capturing genetic variation at IGF1 with these markers, could mean associations were missed.