A one-piece cable tie includes a locking head and an attached strap, the locking head being adapted to receive and selectively engage a portion of the strap when the tie is formed into a closed loop. The cable tie additionally includes an insert fastener formed into the locking head that is sized and shaped to be retained within a rectangular slot formed in a panel. The insert fastener includes apair of spaced apart, parallel arms which extend orthogonally away from an outer end wall of the locking head, a cross-member extending transversely across the free ends of the pair of arms and a pair of offset retention fingers. Each retention finger is connected at one end to the cross-member and is capable of being independentl pivotally displaced along an arcuate path. As a result of the offset design of its retention fingers, the cable tie can be manufactured as a unitary plastic member using simplified and inexpensive molding techniques.