OBJECTIVE- To assess the relationship between leg length and glucose tolerance in pregnancy. RESEARCH DESIGN AND METHODS- The leg length to leg-to-height percentage were prospectively determined on 161 glucose-tolerant women during pregnancy and 61 women with gestational diabetes mellitus (GDM). RESULTS-Women with GDM were a mean of 2.8 cm shorter than women who were glucose tolerand, due entirely to their leg lengths being a mean of 3.2 cm shorter. With respect to the 2-h result on the glucose tolerance test (GTT), there were negative correlations for height (r = -0.161, P = 0.017), leg length (r = -0.266, P < 0.0005), and the leg-to-height percentage (r = -0.294, P < 0.0005). The correlation between the leg-to-height percentage and the 2-h result on the GTT remained significant after adjustment for age (r = -0.252, P < 0.0005) and for age and BMI (r = -0.224, P = 0.001). CONCLUSIONS - Women with GDM are shorter than glucose-tolerant women and have a lower leg-to-height percentage. Consideration of short stature as a risk factor for GDM is not valid without taking into account the leg-to-height percentage.