Fifth metatarsal fractures are common foot injuries that involve the long bone on the outer side of the foot, and avulsion fractures involving the short bone and the fifth distal phalanx of the foot have never been reported. A 25-year-old female marathon runner sustained an avulsion fracture of the distal lateral phalanges of the fifth metatarsal. The patient's high functional demands necessitated a conservative approach to minimize complications and facilitate efficient fracture healing. The patient underwent a comprehensive chiropractic rehabilitation program that focused on progressive weight-bearing exercises, range-of-motion activities, strengthening exercises, instrument-assisted soft tissue mobilization (IASTM), therapeutic ultrasound, and laser therapy to stimulate the speed of healing. The patient's progression was closely monitored throughout the rehabilitation process. Because of the nonoperative management and chiropractic rehabilitation, the patient successfully returned to her running activities within a six-week duration. This case demonstrates the effectiveness of nonoperative management and chiropractic rehabilitation in promoting the healing of avulsion fractures of the fifth metatarsal in high-level athletes. This conservative approach can facilitate a safe and efficient return to running activities while minimizing complications and reinjury risks.