Lemierre's syndrome (LS) is a rare complication of oropharyngeal infections, often causing sepsis, internal jugular vein thrombosis, and metastatic infections. We present a unique case of a 48-year-old male with LS complicated by an internal carotid artery pseudoaneurysm compressing the pituitary gland, resulting in panhypopituitarism. Diagnosis was confirmed via imaging and detection of Fusobacterium nucleatum. Treatment included antibiotics, anticoagulation, and hormone replacement. Although the patient recovered from pituitary deficiencies, growth hormone deficiency persisted. This case emphasizes the importance of recognizing endocrine dysfunctions in LS and highlights the need for multidisciplinary management to address vascular and neuroendocrine complications.