The patient was a 76-year-old female who had a history of Guillain-Barre syndrome 3 years previously; ST-segment elevation was noted in association with reversible left ventricular dysfunction. Left ventrioculogram and coronary angiograms were normal and ergonovine test was negative during the chronic period of Guillain-Barre syndrome. She was hospitalized again due to the recurrence of Guillain-Barre syndrome. Two days later, ST-segment elevation in leads V₂ through V₅ prompted us to perform cardiac catheterization, although she did not complain of any chest symptoms. A large akinetic area was found mainly around the apex on left ventriculography, despite the lack of coronary stenoses. Peak creatine kinase and C-reactive protein were 400 IU/ml and 3.5 mg/dl, respectively. Left ventricular dysfunction was normalized within one week. During the acute phase of the cardiac episode, plasma norepinephrine and epinephrine were 1340 pg/ml and 112 pg/ml, respectively. I¹²³ metaiodobenzyl-guanidine myocardial scintigram 3 weeks after the episode showed an extensive apical defect which was improved markedly 3 months later. We think that this reversible left ventricular dysfunction was due to the synergistic toxic effect of mildly increased catecholamine and transiently damaged sympathetic nerve endings in the myocardium, presumably due to Guillain-Barre syndrome.