For those of us who share our homes with companion animals, there can be no doubt that they have full, rich, and varied personalities. But for many years, scientists were reluctant to describe the unique characteristics that make up each companion animal as personality; in fact, there was active resistance to using the word personality with regards to animals. Fortunately, this has changed over the last few decades, as researchers became not only willing to use the term personality with animals but interested in actively investigating animal personality. These researchers came from a variety of scientific fields and employed a diverse range of techniques but through their efforts, a general picture of animal personality has begun to emerge (for a detailed review, see Jones and Gosling, 2005; Miklósi, 2007; Svartberg, 2007). Since a dog’s personality is such an important factor to consider when making rehoming decisions, the Center for Shelter Dogs is in the process of developing a long-term research program to investigate personality traits and types in dogs. The first project in this program is the identification of canine personality traits detected using the Match-Up Behavior Evaluation. Later projects will focus personality typing, matching to adopters, and personality determinants of successful matches.