A 7.5-year-old castrated male ferret (Mustela putorius furo) was diagnosed with third-degree atrioventricular (AV) block. A monopolar epicardial pacemaker system was implanted, resulting in a regular, paced cardiac rhythm with third-degree AV block at 140 beats per minute. Over the next 2 months, the ferret developed anorexia, interstitial pneumonia, intermittent diarrhea, and hind-limb weakness and had a slow and progressive recovery. The ferret developed clinical signs of congestive heart failure 4 months after the surgery, resulting in its death 3 weeks later. Necropsy results attributed the death to cardiac failure due to extensive myocardial mineralization. To the authors' knowledge this is the first published report of surgical report of surgical pacemaker implantation in a ferret.