Urgent cardiac transplantation in very unstable patients, kept alive in intensive care unit, is a significant (34 percent) part of the Henri-Mondor's transplantation program. Nineteen patients received a donor graft from january 1986 to october 1988. Sixteen were bridged pharmacologically as 5 received a mechanical bridge. Time on waiting list ranged from 12 to 21 days. Six patients died in the first post-operative month. Death was due to uncontrolled preoperative problems in 5, donor graft failure in one. The survival rate at one year was 52 percent, to be opposed to 76 percent in stable patients. These figures must be considered when selecting the priority of the transplantation candidates.