Internal jugular vein catheterization is nowadays a routine procedure in clinical practice. Arterial puncture is the most common complication of internal jugular vein catheterization. Two cases of pseudoaneurysm formation as a complication of accidental arterial puncture in liver transplant patients with coagulopathy are presented. Punctures of the common carotid artery, thyrocervical trunk, respectively were the source for these lesions. Coagulopathy is seen as an essential factor in the formation of pseudoaneurysm. Especially in patients with coagulopathy the threshold for ultrasound guidance should be low. Under these circumstances using the external jugular vein seems to be more prudent as it eliminates the risk for arterial punctures. We illuminate the genesis, signs and symptoms, diagnosis, and therapy of pseudoaneurysm. Recommendations for risk reduction are given.