Pseudoaneurysm is a rare complication after intertrochanteric fracture fixation. Herein, we present a rare case of late development of a pseudoaneurysm with silent clinical symptoms. The case was a 91-year-old woman treated with proximal femoral nailing and cerclage wiring. Postoperatively, the patient was able to ambulate with a walker without abnormal symptoms. During the follow-ups, the radiographic images showed progressive cortical scalloping on the medial femoral shaft. Ultrasonography revealed a yin-yang sign, and a CT scan confirmed a pseudoaneurysm at the profunda femoris artery (PFA). In this case, many possible causes of pseudoaneurysm were hypothesized. We showed that the excessive displaced, long spiral pattern of an intertrochanteric fracture, which was irreducible by a closed technique, is the risk of a PFA injury. An atherosclerotic vessel was seen in preoperative radiography, indicating poor vessel elasticity which may be a risk of vessel tear during fracture reduction using multiple reduction instruments in excessive displaced fracture. Moreover, over-penetration when drilling should not be overlooked. We also discuss the predisposing factors, surgical techniques which may lead to this type of PFA injury and summarize the literature of pseudoaneurysms related to intertrochanteric fracture fixation.