Hyperadrenocorticism is a common and complex clinical condition in the pet ferret. This disease occurs most frequently in ferrets three years or older but has been reported in animals as young as one year of age. Presumptive diagnosis of adrenal disease in the ferret is based on history, clinical signs, imaging diagnostics, and steroid hormone analysis. Medical therapy using deslorelin implants, though not curative, is recommended. Ferrets may remain asymptomatic for a median of 1-1.5 years. Adrenalectomy may be indicated in case non-responsiveness to medical treatment, although adrenalectomy of the right adrenal gland is difficult.