Abstract In this chapter, we discuss the development and use of picture stimuli incorporated in the International Affective Picture System (IAPS, pronounced “eye-aps”; Lang, Bradley, & Cuthbert, 2005), a large set of emotionally evocative color photographs that includes pleasure, arousal, and dominance ratings made by men and women. The IAPS is currently used in experimental investigations of emotion and attention worldwide, providing experimental control in the selection of emotional stimuli, facilitating the comparison of results across different studies, and encouraging replication within and across psychological and neuroscience research laboratories. Numerous studies in our laboratory over the past 15 years have explored subjective, psychophysiological, behavioral, and neurophysiological reactions when viewing these affective stimuli. Basic findings from these studies, which will be informative for researchers considering or using the IAPS stimuli, are briefly summarized in this chapter.