In the course of our study of the comparative anatomy and physiology of the mammalian heart, it became necessary to develop a technic to obtain the electrocardiogram of the largest mammal of all. Because of its availability, the small white Beluga whale in northern waters was the first object of this research, prior to obtaining the record of a large whale, which is our ultimate aim. This article describes the process of obtaining the electrocardiogram and presents the electrocardiogram itself.