This chapter reviews the psychological research on the concentration processes of athletes. As confirmed by the quotations from psychologists and sport performers, such processes are regarded as being crucial determinants of athletic success. The chapter examines what the term concentration means in sport psychology. It reviews the research findings on selective and divided attention in sport performers. The chapter will also feature a brief treatment of the issue of expert-novice differences in concentration skills. It sketches some of the theoretical and methodological benefits for sport psychology which stem from conducting research on concentration in athletes. Little or nothing appears to be known about the advance auditory or tactile cues that are used by athletes to make predictions in their sport. Bearing this limitation in mind, certain research findings have emerged. Most of these findings come from studies using either the cue-occlusion paradigm or some form of eye-movement recording technology.