Pseudolupus is a syndrome characterized by recurrent fever arthralgia, myalgia, involvement of lung and heart, high sedimentation rate, leukocytosis and lymphopenia. The diagnosis is established by the presence of circulating antimitochondrial antibodies. In 1975 it was found that the disease was due to prolonged treatment with Venocuran, a drug against venous disorders composed of phenopyrazone (pyrazolone derivative), horse-chestnut extract, and Miroton (glycosides extracted from white squill [Urginea maritima], convallaria, oleander and adonis). The drug was then withdrawn. No new cases have come to our attention since then. 15 patients with severe pseudolupus known to us in 1975 have now been followed up. In 6 of the patients all symptoms disappeared within weeks or a few months after withdrawal of the drug. However, the other 9 patients had at least 1 and often 2--3 relapses in the following months to years. In some patients, symptoms remained as long as 4--5 years. Antimitochondrial antibodies persisted in 4 patients for more than 3 years and in 1 patient are still detectable now. The pathomechanism of pseudolupus has not been elucidated.