In the United Kingdom, each year many companion animal (pet) caregivers (owners) hand over dogs to shelters for rehoming. Studies conducted in the United States and Australia have shown that accommodation issues and problematic behaviors are the most common reasons for dogs to be relinquished. The purpose of this study was to provide a clearer understanding of common characteristics of relinquished dogs in the United Kingdom. A descriptive study conducted during 2005 collected data on 2,806 dogs relinquished to Dogs Trust's rehoming centers in the United Kingdom. The most common reasons for dogs to be relinquished were their problematic behaviors and their need for more attention than the owner could provide. The results of this study identify several common characteristics of relinquished dogs as well as differences between its results and those found in studies conducted in the United States and Australia. An improved knowledge of characteristics of relinquished dogs should inform the development of strategies for improved management of the rehoming process.