Abstract: An ultrasonic cable tie system is disclosed herein. The ultrasonic cable tie system includes a housing having a tying portion for receiving a bundle of wires to be tied into a cable. The tying portion has an aperture for dispensing a cable lacing filament from a filament spool and for receiving a free end of the cable lacing filament after being positioned around the bundle of wires. The ultrasonic cable tie system also includes a controller coupled to a tensioning member for tightening the cable lacing filament, an ultrasonic welder for fusing the cable lacing filament, and a filament cutting device for cutting the cable lacing filament. The ultrasonic cable tie system is activated by a system actuator causing the controller to secure the bundle of wires together into the cable with the cable lacing filament having a flat fused portion adjacent to a surface of the cable.