Why is it so hard to choose the fruit salad instead of the chocolate cake? Why do we dread our daily workout? And why do some of us find it so difficult to quit smoking, quit drinking too much, or stop using drugs? This chapter argues that these unhealthy behaviors are largely a function of hedonic motivation: an automatically triggered motivational state that manifests in a felt desire to perform behaviors that have previously brought immediate pleasure, or dread of performing behaviors that have previously brought immediate displeasure. The concept of hedonic motivation is based on recent developments in the fields of affective neuroscience (i.e., incentive salience theory) and psychology (i.e., dual-processing theory) and is positioned herein as the central mechanism of the ancient and intuitive theory of psychological hedonism. Greater attention to hedonic motivation is critical for understanding behaviors that account for a significant proportion of worldwide death and disease.