The loss of a pet, whether due to the death of the animal or any other cause of separation, can be the impetus for acute grief responses in individuals of all ages. In 1981, the author completed an in-depth study that explored and reported descriptions offered by pet owners of the deaths of their pets and their perceived associated responses. This paper will examine the thinking and research in the area of human responses to pet death using the results of the author’s study to highlight the major concepts.