The Toyobo-NCVC extracorporeal pneumatic left ventricular assist system (LVAS) was used in four patients with advanced dilated cardiomyopathy. The duration of support ranged from 46 to 390 days (mean, 206 days). In all patients, stable hemodynamics were achieved with 3.5-5.5 L/min flow rates. Two patients survived long term. One was transported to the United States by a chartered jet while on LVAS and successfully underwent heart transplantation after 119 days of support. The other is on LVAS and is doing well for 390 days. The remaining two patients died of multi-organ failure while their hemodynamics were quite stable under LVAS. In these two patients, severe hepatic failure had developed before LVAS implantation. Minor cerebral embolisms occurred in the two survivors, but neither of them experienced permanent neurologic deficits. In only the initial patient were major thrombi noted on the diaphragm of the pump; the thrombi required pump exchange four times during 119 days. In the patient supported for 390 days, a small tear in the diaphragm was observed after 209 days of support, and the pump was safely exchanged. It is suggested that the Toyobo LVAS can provide consistent and reliable performance for long-term use.