Avulsion fractures of the pelvis occur in both the skeletally immature and adult patient populations the patho-mechanism is the sudden forceful contraction of the related muscle. The case reported here is an overlooked case of anterior inferior iliac spine avulsion fracture in a 25-year-old man, misinterpreted as malignant pathology. Avulsion fractures of the anterior inferior iliac spine can be diagnosed with medical history and radiological methods. The physician must be cautious during the assessment of the patient with complaint in his/her groin and keep in mind the possibility of an anterior inferior iliac spine fracture.