A multi-lumen catheter including an elliptical cross-sectional profile configuration that enhances fluid flow rate while minimizing the average diameter of the catheter body is disclosed. In one embodiment the catheter comprises an elongate catheter tube defining a plurality of lumens. At least a portion of the longitudinal length of the catheter tube defines an elliptical cross section, in turn defined by a major axis and a minor axis. A ratio of the major axis to the minor axis of the elliptical catheter tube cross section is between about 1.3 and about 1.4 in one embodiment. The catheter body can define two, three, or more lumens, in one embodiment.