Eucithara guentheri is a small sea snail, a marine gastropod mollusk in the family Mangeliidae.

This solid shell with an elongated conical shape has an acuminate apex.

It is delicately sculptured with longitudinally ribs, latticed by revolving striae.

The columella is slightly curved and contains a white callus.

The outer lip is thickened and has a sharp edge.