20 cases of cerebral arteriovenous malformations (AVM's) are reported, treated by direct intraoperative embolization. A 50% mixture of butyl-2-cyanoacrylate (IBC) and ethyl mono-iodostearate (Duroliopaque) was used. The clinical history of the patients was a long history of seizures in 10 cases, a haemorrhage in 9 cases, and a motor deficit in 1 case. In the immediate post-operative course, 1 patient died, 3 patients had a serious post-operative haemorrhage, 6 patients presented with a transient post-operative deficit, and in 10 patients the post-operative course was uneventful. During the following years, a late haemorrhage occurred after incomplete AVM eradication in 3 patients, leading to AVM resection. The AVM eradication was eventually complete in 3 cases with embolization only, and in 7 cases with embolization and AVM resection. The overall management of AVM in all 20 patients was: embolization only in 13 cases, embolization and resection in 7 cases. The long term results are: operative death 1, late death 3, long lasting deficit 1; uneventful 15. The authors discuss the technique of embolization, the effect of IBC on the vessel walls, the evolution of their general management of AVM's after this experience. Eventually the intra-operative embolization may be helpful after incomplete intra vascular embolization, to facilitate the AVM eradication.