Psychophysiology is the study of the physiological representation of the psychological state. In golf and sport it allows for data to be collected just prior to performing motion as an indicator of preparation for performance. Typical measures recorded during golf and sport performance include electroencephalography (EEG), heart rate (HR) and electrodermal responses (EDR) of the skin. These data are often compared among elite and novice golfers (inter-golfer comparisons) and between best and worst performances (intra-golfer comparisons). In addition, different experimental conditions (i.e., increased stress) may be compared to baseline measures of performance and to rest conditions. Psychophysiological measures can also be used in a feedback paradigm. Auditory or visual feedback provides the golfer with real-time indicators of their psychophysiological state and can be used to train the golfer to optimize this. Lastly, electrical stimulation (i.e., brain) provides frequency stimulation to enhance learning and performance. This chapter will provide a basic description of the psychophysiological measures used in golf and sport. Golf research results will be discussed along with applicable research from similar sports such as archery and marksmanship. A research summary, future directions and application of these findings will be presented.