A high impact strength lighted nock assembly for an arrow that is activated when the arrow is fired with a bowstring. The lighted nock assembly includes a nock molded from a high impact strength, transparent polymeric material containing at least 10% by weight reinforcing fibers. The nock includes a head configured to engage with the bowstring and a shank configured to couple with a rear end of the arrow. The shank includes a recess extending in a distal end of the shank toward the head. A light assembly including a light emitting device is located in the recess in the shank that is electrically coupled to a battery. A switch is electrically coupled to the light emitting device and the battery that is triggered when the arrow is fired to activate the light emitting device.