Our two patients accidentally ingested selenium orally at a concentration 10 times higher than that intended. As a result, clear symptoms of acute selenium intoxication were noticed a few days later. The determination of the selenium level in serum revealed for both patients concentrations that were three times above the normal range.Only a few cases of acute selenium intoxication in humans have been reported previously. In these cases, the most common symptoms described, among others, were nausea and diarrhoea. However, according to the literature death resulting from haemolysis and cardiovascular failure occurred after poisoning with exceptionally high doses. 2,4,6,7 In commercially available selenium preparations, such as sodium selenite, daily dosages of 100 lg are recommended, which reach 300 lg on a short-term basis. It is known that orally or parenterally administered selenium has a limited therapeutic range. 4 No agreement has been reached in the literature regarding the safe upper limit of selenium intake. Studies on selenium in humans revealed that toxic effects occur following a daily intake of at least 300 lg.Noncritical intake of selenium without a physician's recommendation has to be urgently dissuaded. Our two cases show that during the administration of selenium, for example as part of a fasting treatment, it is necessary to consider its limited therapeutic range in order to avoid an overdose and related toxicity. Fig 1. A subcutaneous deep-seated nodule with cutaneous horn 7 · 7 mm in diameter on the left periocular area.