Nursing research in veterinary hospitals is critical to the work of veterinary nursing and is necessary for continued advancements that promote optimal nursing care. Since the work of veterinary nursing involves animals with whom communication is difficult, the level of work performance can vary greatly depending on the experience, knowledge, and abilities of each animal nurse. In addition, veterinary nursing might establish a successful work environment through collaboration with veterinarians, and smooth work cooperation and communication among hospital members are direct factors in improving the work performance of animal hospitals. Because the work of nursing shows significant differences in performance depending on the individual, much research is being conducted to develop tools to measure work performance in the veterinary nursing field of medical assistants. In the present study, we attempted to develop a work performance measurement tool that is useful and suitable for veterinary nursing using the Delphi method. As a result of this study, an 18-item questionnaire was developed to measure the work performance of veterinary nursing, and these evaluation items were found to have excellent suitability in terms of content and construct validity. The evaluation scale of work performance of animal nurses developed through this study is believed to be useful in evaluating work performance in terms of work performance ability, attitude, and work performance relationship. Additionally, it is considered that the results of this study can be actively used to understand and develop the work relationships of veterinary nursing.