The aim of this study was to evaluate mid- and long-term results of ultrasonically guided ethanol injection into parathyroid adenomas. From 1988 to 1996, 27 patients (mean age 77 +/- 13 years) were treated for parathyroid adenomas by percutaneous ethanol injection. The survey included clinical information, plasma calcium, phosphorus and PTH (1-84) evaluation. Follow-up lasted 22.6 +/- 10 months. No major complications were observed for 63 ethanol injections. Biochemical recovery was 58%, biochemical improvement at 3 months was 33%, and failure was 7%. Four of 15 cured patients presented a recurrence of the disease 1 or 2 years after the first treatment. Ultrasonically guided ethanol injection can be useful in the treatment of parathyroid adenomas when surgery is not possible. The immediate results are interesting but not as good as those obtained with surgery. A regular biochemical survey is necessary so that recurrences can be recognized and treated at an early stage.