To evaluate the association of variables of body habitus with direct measurements of ureteric length, as the correct choice of ureteric stent length might help to prevent complications and improve stent tolerance, and to date there are limited data correlating height or other body variables with ureteric length. We prospectively measured pelvi-ureteric junction to vesico-ureteric junction length in 100 patients by placing a ruled 5 F ureteric catheter. Ureteric length was then correlated with patient height, weight, body mass index, and distance from the shoulder (acromium process) to the wrist (head of the ulna; S-W), the elbow (olecranon process) to the wrist (head of the ulna), xyphoid process to umbilicus, xyphoid process to pubis (X-P), umbilicus to pubis, and anterior iliac spine to anterior iliac spine. Patients with pathology affecting the ureteric length were excluded. The results were analysed statistically using a multiple linear regression model with stepwise selection of variables, and a paired t-test. The mean right and left ureteric lengths were similar (P=0.61); height (P<0.01), weight (P=0.02), X-P (P=0.01), and S-W (P=0.02) distances all correlated with ureteric length. On multivariate regression analysis, weight, height and male gender were associated with mean ureteric length. From these data a formula was constructed to predict ureteric length. It is a challenge to predict ureteric length from body habitus, but height, X-P distance and S-W distance can be used to predict ureteric length.