Thalidomide is a drug with bad reputation from the 1960's as it appeared to be teratogenic by causing foetal anomalies. However, in the beginning of 1990s it was shown very antiangiogenic. Its immunological effects were known already from earlier studies. Nowadays its use is accepted in myeloma therapy. It is also used in many study protocols, e.g. in pediatric patients with brainstem tumors. Thalidomide should be used very cautiously for fertile patients because of its teratogenity. Other adverse effects are tiredness, obstipation, thrombosis, and polyneuropathy.