A removable or absorbable vena cava filter is introducible through a relatively small bore catheter. These filters formed of a single high-memory wire. The wire has a coiled cylindrical portion and a coiled conical portion. The wire assumes a straight configuration when in a catheter. The coils of the cylindrical portion have a sufficiently large diameter contact the walls of the inferior vena cava with sufficient force to hold the coils in place against the inferior vena cava. The cylindrical portions of the wire has an anchor attached to it in a non-absorbable embodiment of the invention. The conical portion of the wire has a segment which aids in the removing of the filter from the vena cava.