A rheolytic thrombectomy catheter and method of using same to remove thrombus from a body vessel or other body cavity. Several embodiments are disclosed. All embodiments include an outer catheter having a lumen and an inner high pressure tube of a size to enable it to be passed through the lumen of the catheter. The distal end of the inner high pressure tube extends beyond the distal end of the catheter and carries a jet cap for directing one or more jets of saline proximally toward the distal end of the catheter. In some embodiments, the catheter has a distally located inwardly directed stationary stop and the inner high pressure tube includes a distally located outwardly directed transitional stop for engaging the inwardly directed stationary stop to thereby position the jet cap at a defined distance from the distal end of the catheter. In other embodiments, a stationary stop is located at the proximal end of the catheter and a transitional stop is carried on the proximal end of the inner high pressure tube. In the embodiments having the stationary and transitional stops located proximally, the inner high pressure tube includes a flow director at its distal end. In use, thrombus is dislodged, entrained, and broken into pieces by the saline jets and evacuated proximally through the lumen of the catheter.