Abstract 53 patients leaving hospital after an episode of ventricular fibrillation (V.F.) complicating acute myocardial infraction have been followed up for six months and 41 of them have been followed up for over one year. The mortality-rate, work record, and clinical status of these patients indicate that the episode of V.F. did not adversely affect the long-term prognosis. Patients surviving primary V.F. did especially well. The first-year mortality-rate for this group was 7%. After one year 92% of male patients surviving primary V.F. were able to return to work and 67% had returned to the same job.