The purpose of this study was to investigate the hypothesis that a repetitions-to-maximum test is a predicator of a 1 repetition maximum (1RM) performance for evaluating upper and lower body strength in women high school athletes. Fifty-seven high school athletes ages 14-18 participated in this study. All of the participants completed a 1RM bench (1RMBP) and leg press (1RMLP) test, as well as leg press repetitions-to-fatigue (91 kg; LPRTF91) and bench press repetitions-to-fatigue (27 kg; BPRTF27) tests. A Pearson product correlation and regression analysis was used to determine relationships between 1RM strength and the repetitions-to-fatigue for upper and lower body strength. On the basis of the data analysis, it was concluded that BPRTF27 had a high correlation with 1RMBP strength (r = 0.802) and LPRTF91 had a correlation with 1RMLP strength (r = 0.793), indicating that these test measures were viable alternatives to 1RM testing for strength assessment. A regression analysis further confirmed that BPRTF27 was a significant variables in developing the model 1RMBP = 28.88 + (0.68)BPRTF27 for predicting upper body strength (p < 0.001). Similar results occurred 1RMLP = 106.3 + (2.4)LPRTF91 in developing the lower body model (p < 0.001). From data analysis, it was concluded that repetitions-to-fatigue testing can be used to evaluate upper and lower body strength in women high school athletes.