Although sport psychologists utilize numerous interventions and techniques intended to enhance the performance of athletes in competition, the selection of those interventions has not always been based on research for which adequate validity has been established. In an attempt to provide sport psychologists with a working body of accurate knowledge and suggestions for future intervention research, an analysis and synthesis of research is presented that addresses the efficacy of different psychological interventions with athletes performing in competitive situations in the sport in which they regularly compete. From information reported in 19 published studies, covering 23 interventions, it was concluded that educational relaxation-based interventions and remedial cognitive restructuring interventions with individual athletes are, in general, effective.