Studies on cardiopulmonary resuscitation (CPR) are limited in veterinary medicine. The recent Reassessment Campaign on Veterinary Resuscitation (RECOVER) greatly contributed to the knowledge of cardiopulmonary arrest (CPA) and factors that affect CPA outcomes and survival. In this prospective study, performed before publication of RECOVER, the authors examined factors that may improve or impair CPR outcome in dogs and cats. The study included 121 dogs and 30 cats that underwent CPR at a university hospital. Return of spontaneous circulation (ROSC) was achieved in 70/121 (58%) of dogs and 17/30 (57%) of cats. However, only 10% of dogs and 10% of cats were alive 24 hours after CPR, and only 6% of dogs and 3% of cats survived to hospital discharge.