The capability for studying noninvasively vessels has been dramatically improved with the use of gradient echo sequences. Twenty-one patients presenting a suspected inferior vena cava obstruction on cavography underwent MR examination with axial, sagittal and coronal gradient echo images. Eighteen patients were also imaged with ultrasound and/or CT. Gradient echo sequences visualized a thrombus in 19 cases and a normal vein in the remaining 2 cases. The potential MR pitfalls are illustrated and the two cases of false positive on cavography are discussed. Gradient echo sequences allow a fast and performant examination of the vessels.