Millions of people in the United States are living with a serious mental illness or substance abuse disorder. These individuals suffer from a high rate of medical co-morbidities. Because of this, patients hospitalized on medical-surgical units for medical reasons often are living with psychiatric/substance abuse co-morbidities, which are not addressed during their medical hospital admission. These patients can be perceived as difficult and even dangerous by nurses who have not received training or education in mental health care. The purpose of this project is to measure medical-surgical nurse’s perceptions of their abilities to recognize psychiatric/substance abuse symptoms and their perception of self-competency to provide appropriate interventions. This project utilized the Behavioral Health Care Competency (BHCC) instrument to measure hospital nurse perceptions of behavioral healthcare competency to determine if additional education and training are needed. The BHCC tool was administered to 19 nurses working on two medical-surgical units in Southern Arizona. Findings support the need for educational intervention, especially in the areas of psychotropic medication recommendation and intervention for patients experiencing hallucinations.