Naclerio, F and Larumbe-Zabala, E. Relative load prediction by velocity and the OMNI-RES 0–10 scale in parallel squat. J Strength Cond Res 31(6): 1585–1591, 2017—This study analyzed the possibility of using movement velocity and the rate of perceived exertion as predictors of relative load in the parallel squat (PSQ) exercise. To determine the full load-velocity and load-rate of perceived exertion relationships, 290 young, resistance-trained athletes (209 males and 81 females) performed a progressive strength test up to the 1 repetition maximum. Longitudinal regression models were used to predict the relative load from the average velocity (AV) and the OMNI-RES 0–10 scale, considering sets as the time-related variable. Two adjusted predictive equations were developed from the association between the relative load and the AV or the rate of perceived exertion expressed after performing several sets of 1–3 repetitions during the progressive test. The resulting 2 models were capable of estimating the relative load with an accuracy of 79 and 86% for the AV (relative load [% 1 repetition maximum, RM] = 120.15–83.54 [AV]) and the exertion (relative load [% 1RM] = 5.07 + 9.63 [rate of perceived exertion]), respectively. The strong association between relative load with AV and the rate of perceived exertion supports the use of both predictive variables to estimate strength performance in PSQ.