A case of post-traumatic proximal peroneal artery pseudoaneurysm following a proximal tibial shaft fracture, complicated by acute compartment syndrome, fixed using an external fixator, in a 22-year-old female is presented. She was investigated for sudden-onset bleeding from the external fixator pin site, 6 weeks after the initial injury, was anaemic and diagnosed with a pseudoaneurysm at lower limb angiography. Contrast leak from the site of pseudoaneurysm was noted and open surgery with ligation of the pseudoaneurysm was performed. This rare complication of a proximal tibial shaft fracture has to be considered in patients presenting with acute bleeding from the surgical site or from pin sites after a significant lag period and requires a high index of suspicion.