OBJECTIVE To evaluate the results of partial and total ossicular reconstruction prostheses entirely made of hydroxylapatite. STUDY DESIGN A retrospective review of cases followed-up between 1997 and 2000. SETTING Tertiary referral center. PATIENTS One hundred adult patients (60 men and 40 women) were studied. The mean age was 55 years (range, 25 to 65 years). Fifty patients had a previous tympanoplasty. The series included 45 cholesteatomas (45%), 37 chronic otitis media without cholesteatoma (37%), 13 retraction pockets (13%), and 5 posttraumatic ossicular displacements (5%). INTERVENTION A one-stage ossiculoplasty with a partial ossicular reconstruction prosthesis (n = 65) or a total ossicular reconstruction prosthesis (n = 35) was performed. This was associated with a simple mastoidectomy in 70 cases and a radical mastoidectomy in 10 cases. MAIN OUTCOME MEASURES All patients were followed-up at 1 year, and 50 were reexamined 2 years after surgery. Clinical and audiometric data were collected in a database at each visit. RESULTS A prosthetic extrusion was noted in two cases (2%). A prosthetic displacement occurred in 10 cases (10%). A revision surgery was carried out in 10 cases because of an ossiculoplasty failure or a disease recurrence. At 1 year, the residual air-bone gap was lower in cases with a partial ossicular reconstruction prosthesis than those with a total ossicular reconstruction prosthesis (16 +/- 9.3 versus 23 +/- 13.7 dB, p < 0.05). The gain in mean air conduction threshold was 21 +/- 12.8 dB in cases of partial ossicular reconstruction prosthesis and 19 +/- 11.3 dB in cases of total ossicular reconstruction prosthesis (not significant). Revision surgery, canal wall-down mastoidectomy, or cholesteatoma yielded poorer functional results. CONCLUSION Partial ossicular reconstruction prosthesis and total ossicular reconstruction prosthesis entirely made of dense hydroxylapatite yielded high rates of air-bone gap reduction and high anatomic stability.