In a previous study, we showed that the Vitalmex Extracorporeal Ventricular Assist Device-Pneumatic (EVAD-P)-a low-cost, pneumatically actuated, pulsatile blood pump-is easy to implant and safe for short-term in vivo support (30 ± 5 days). In the current study, we included additional 30 day experiments and assessed the safety and durability of the EVAD-P for up to 90 days of support. Using the same surgical procedure as in the previous study, we implanted the device into 14 healthy sheep. Group I subjects (n = 7) were evaluated for up to 30 days, and group II (n = 2) and group III (n = 5) subjects were evaluated for up to 49 and 93 days, respectively. After a system redesign, two of the five sheep in group III reached the scheduled end-point without device-related problems at a fixed beat rate of 56 bpm, a stroke volume (SV) of 58.0 ± 2.3 ml, and a flow of 3.5 ± 0.2 L/min. This study shows that the EVAD-P can provide safe pulsatile mechanical circulatory support (MCS) for up to 93 days. To further confirm that the system can consistently provide MCS for this duration, additional studies are recommended.