The objective was to evaluate the long-term clinical outcome of the bony outer attic wall reconstruction (scutumplasty) by using autogenous bone paté in a series of patients who underwent canal wall up (CWU) mastoidectomy for middle ear cholesteatoma. In addition, an histological analysis of bone paté graft specimens taken during the second-look procedure 12 months after the first surgery, was carried out. A series of 134 ears from 128 patients with cholesteatoma who underwent staged CWU mastoidectomy and attic reconstruction with bone paté, between 1995 and 2000 inclusive, was retrospectively analyzed. In ten randomly selected ears, biopsies from the newly built outer attic wall were taken during the second-look operation and were microscopically analyzed. At the second stage operation, the bone paté graft was found normal in 64.9% of cases. In 39 (29.1%) patients there was a remarkable hypertrophy of the bone paté which was subsequently thinned out by using a diamond burr. A partial resorption of the bone paté was observed in 4.4% of ears and a total resorption in 1.4%. Residual cholesteatoma was found in 13.4% of ears. At the last follow-up visit, recurrent cholesteatoma was observed in 5.2% of ears. Self cleaning attic retraction pocket occurred in 4.4% of ears. Twelve months after implantation, histologic examination on the newly built bone showed a well-structured bony tissue. In particular, osteoblasts lined bone trabeculae with signs of an active tissue remodeling. In conclusion, the reconstruction of the outer attic wall should be considered a fundamental step when performing a CWU procedure in order to prevent attic retractions and recurrences of cholesteatoma. In our experience, autogenous bone paté graft has demonstrated good long-term results in outer attic wall reconstruction being adaptable, well tolerated, stable and of low cost.