A device for loading a guide wire into the open end of a tubular instrument such as a catheter. The device can be a block of material having a groove in its surface. The ends of the guide wire and the tubular instrument are placed into the groove and moved toward each other. When the ends meet, the groove guides the guide wire into the open end of the tubular instrument. The groove, or at least a portion of the groove, can have a cross-sectional contour that closely matches the outside radius of the tubular instrument. The groove can have one portion with a shallower depth than the other portion, with the guide wire run in the shallower portion and the tubular instrument in the deeper portion. The guide wire and the tubular instrument can be angled above the device, with just their ends moving along the groove.
