The debate regarding the efficacy of single set strength training to elicit similar strength improvements as multiple set protocols has continued in recent years. While a number of studies have provided data to support this efficacy, the mean statistical power of all studies comparing single and triple sets of training was estimated to be .56. The lack of statistical power among this research may result in the inability to identify a significant difference between treatments despite its existence. Therefore, a meta-analysis was performed to examine single and multiple sets of weight training for strength. Studies comparing single and three sets of training were analyzed and effect sizes (ES) were calculated by training status, length of training program, and control for training intensity and variation. Significant ESs were measured for both trained (.46) and untrained (.19) subjects at all lengths of training programs. Those studies that controlled training variables such as intensity and periodization were found to elicit a significantly greater ES (.70) than those who failed to control these variables (.25). Thus, multiple sets elicit greater strength gains than single set protocols with the magnitude of the effect being influenced by training status of the subjects, length of training program, and methodological control.Keyword(s): exercise/fitness, measurement/evaluation, performance