The induction of dysrhythmias during or after pulmonary artery catheterization is a serious complication in critically ill patients. The following case presentation reports the incidence of life-threatening ventricular tachycardia after catheterisation in a patient known to have Wolff-Parkinson-White (WPW)-Syndrome. The dysrhythmia began during repositioning of the patient 10 h after placement of the catheter. Attempted inversion by administration of Ajmalin was unsuccessful. Removal of the catheter resulted in prompt cessation of the dysrhythmia.