Patients who do not require hospitalization or overnight stay in the hospital can be treated via outpatient care; these patients are known as outpatients. Patients who attend appointments at a hospital or clinic for any check-up or aftercare following treatment are also considered outpatients. The popularity of outpatient care has increased because of technological advancements such as minimally invasive surgery. Ear, nose, and throat (ENT), heart, kidney, and orthopedic surgeries can be performed at outpatient facilities because of these new techniques. Technology and patient consumerism are two of the top factors contributing to the growth of outpatient facilities such as ambulatory surgery centers (ASCs), primary care clinics, and urgent care centers, according to Definitive Healthcare's 2019 outpatient trends report. Hospital-based outpatient services can be broadly classified into five main types: clinical, surgical, emergency, home health, and women's health. Other types of outpatient services include school health, office health, outpatient mental health, and others that are newly emerging. Recently, telemedicine-based follow-up has proven to be feasible and safe for the evaluation of early postoperative complications. Patients reported high levels of satisfaction with the experience. As such, telemedicine-based follow-up could become standard practice with the development of mobile applications. One of the most facilitative aspects of outpatient care is that it can be accomplished in non-medical institution-based settings, such as schools, prisons, offices, and more. Outpatient care is likely to become even more popular with the advancement of technology to support it. This work would not have been possible without the support of IntechOpen. I am especially indebted to Author Service Manager Mr. Josip Knapić, who has been supportive of this project and who worked actively to provide me with all facilities. I am grateful to all of those with whom I have had the pleasure to work during this project. Each of the chapter authors provided me with extensive professional help and obliged me on this scientific venture wherever possible. Nobody has been more important to me in the pursuit of this project than the members of my family. I would like to thank my late parents, Taufiquz Zaman and Jaiba Zaman, whose love and guidance are with me in whatever I pursue. Most importantly, I wish to thank my loving and supportive wife, Mrs. Jarin Tanwir Hussain, who is my ultimate role model, and my two wonderful children, Naushad Muntasir Zaman and Umar Sarwar Zaman, who provided me with unending inspiration during the preparation and publication of this book.