Purpose: The purpose of this study is to evaluate the clinical and radiographic results of symptomatic bunionette treated with a diaphyseal oblique osteotomy. Materials and Methods: We retrospectively reviewed 12 feet of nine patients diagnosed as symptomatic bunionette and treated with diaphyseal oblique osteotomy. All patients were female and the average age at the time of surgery was 48 years. We checked the foot standing anteroposterior, oblique, and lateral images pre- and post-operatively. We measured the fourth intermetatarsal angle and fifth metatarsophalangeal angle and evaluated the clinical results using the American Orthopaedic Foot and Ankle Society (AOFAS) lesser metatarsophalangeal-interphalangeal (MTP-IP) scale preoperatively and six months postoperatively. Results: Of the nine patients, hallux valgus was combined with symptomatic bunionette in seven feet of five patients. In all of our cases, the average AOFAS lesser MTP-IP scale showed improvement after surgery. Painful callosity around the fifth metatarsophalangeal joint disappeared after surgery in all of our cases. The fourth intermetatarsal angle improved from $12.7^{circ}$ to $3.1^{circ}$ and the fifth metatarsophalangeal angle improved from $16.6^{circ}$ to $2.3^{circ}$. Conclusion: Diaphyseal oblique osteotomy of the fifth metatarsal appears to be a safe and satisfactory surgical procedure for treatment of symptomatic bunionette.