Permanent obliteration of the eustachian tube via the middle ear traditionally has met with limited success. Combinations of muscle, fascia, adipose tissue, bone fragments, and inert material such as Proplast have been used to seal the middle ear from the nasopharynx by inciting a fibrous reaction within the lumen of the eustachian tube. Long-term follow-up has demonstrated repneumatization of the middle ear cleft in the majority of cases, indicating failure of the obliteration technique. This report describes a technique for successful long-term obliteration using hydroxyapatite cement. This new biomaterial possesses osseointegrative and osseoconductive properties that result in permanent obliteration by producing new bone formation within the lumen of the eustachian tube. This technique eliminates the complication of cerebrospinal fluid rhinorrhea in lateral skull base procedures that expose the eustachian tube to cerebrospinal fluid.