Purpose: This retrospective study investigated the predictability of the osteotome technique for sinus floor elevation in the presence of antral pseudocysts. Materials and Methods: A retrospective study was carried out in patients treated with the osteotome technique for sinus floor elevation in the presence of antral pseudocysts and simultaneous implant placement between 2005 and 2009. Pseudocyst cases were collected from the patient population during that period based on faint dome-shaped radiographic findings in the elevated sinus floor. Data were recorded and evaluated in terms of bone gain and alterations in the sinus floor and peri-implant parameters. Results: Twenty-one patients were diagnosed with antral pseudocysts in the sinus floor, with 21 implants placed underneath. All implants osseointegrated uneventfully, and all but one implant radiographically appeared to gain bone around the apex. Mean residual bone height was 6.85 ± 1.22 mm and the mean length of implants protruding into the sinus was 2.96 ± 1.16 mm. The mean endosinus bone gain after the healing period was 3.40 ± 1.78 mm, with an average crestal bone loss of 0.85 ± 0.42 mm. Thirteen implants showed healed bone graft extending all around the apices, three implants had major bony coverage (50% to 100%) of the apically protruding portion, and four implants showed less coverage ( 50%). The survival rate of implants was 100% (mean follow-up, 27.26 ± 15.22 months), and at that time, mean crestal bone loss was 0.50 ± 0.33 mm, modified Plaque Index was 1.30 ± 0.67, modified Bleeding Index was 0.60 ± 0.70, and mean probing depth was 3.35 ± 0.74 mm. Conclusion: Based upon a retrospective study of 21 implants placed beneath pseudocysts for a mean time of 27 months, it appears that implants that extend into the maxillary sinus can remain functionally stable after osteotome sinus elevation in the presence of antral pseudocysts. Schlagwörter: antral pseudocyst, dental implants, osteotome technique, sinus floor elevation