Psychiatric factors play a significant role in the transmission and perpetuation of the human immunodeficiency virus (HIV) pandemic. In less than four decades, competent HIV medical care and research transformed acquired immune deficiency syndrome (AIDS) from a rapidly fatal illness of unknown cause into a chronic manageable illness. These vast strides made in the care of persons with HIV have not been matched in the prevention of HIV transmission or in the psychiatric care of persons with HIV/AIDS. Although AIDS is an entirely preventable infectious illness, HIV transmission continues throughout the world. HIV transmission of HIV is fueled by the stigma of mental illness and of HIV, as well as discrimination, criminalization, and risky behaviors. A comprehensive biopsychosocial approach to sexual health and mental health and diminution of stigma is essential to both HIV prevention and HIV care. This chapter introduces the concept of HIV/AIDS as “the great magnifier of maladies” as it traces the history of HIV psychiatry, explores the paradoxes and disparities of HIV care, explains how HIV psychiatry is a paradigm for the psychiatric care of the medically ill (psychosomatic medicine), and sets the stage for an understanding of how integrated care can prevent transmission of HIV and decrease morbidity and mortality in persons with HIV.