During mastoidectomy a hollow-cavity is formed within the mastoid bone after its cortex and air cells are removed. Postoperatively, the aerated cavity is usually filled with soft tissues. Also it is not so uncommon to see cases with retraction of the mastoid area skin into the cavity causing a cosmetic problem termed as mastoid dimpling. In order to achieve an aerated mastoid cavity and minimizing the mastoid dimpling, an adhesion barrier was utilized to prevent fibrous tissue formation within the cavity. Twenty-one patients with middle ear and/or mastoid cholesteatoma, who underwent tympanoplasty with mastoidectomy (canal wall-up) with staged procedures, were included in the study. The mastoid cavity was tented and covered with an adhesion barrier (hyaluranic acid and carboxymethylcellulose, Seprafilm, (Seprafilm, GENZYME Inc., Cambridge, MA, USA) at the end of the surgery. Postoperatively, in two cases serohemorrhagic fluid collected between the adhesion barrier membrane and the subcutaneous tissues requiring drainage. Second stages were performed 4-6 months after the first stage. Two residual cholesteatoma cases were present. Patients were followed for a minimum of 2 years after the second stage. Mean follow-up was 2 years and 5 months. No wound infection was encountered postoperatively. Late follow-up of minimum 2 years after the second surgery revealed cosmetically acceptable retroauricular area with no dimpling. Mild retraction in two cases and two micro-central perforations in the neotympanic membrane were found. CT scans obtained both prior to the second stage and at the end of the second year of second stage revealed fully aerated mastoid cavities covered with periosteum in its natural position. Mastoid cortex plasty with seprafilm offers a rapid and effective solution to the preservation of mastoid space and the preservation of the contours of the mastoid bone.