This study aimed to analyze the intrasession reliability of the rate of force development (RFD) in different time windows in squat jumps (SJ) performed at different knee starting angles, and identify the relationship of RFD with vertical jump height (VJH). Twenty male volleyball and basketball players participated. Athletes randomly performed SJ from four different knee-flexion angles. The RFD was analyzed from six different windows, from force onset to instant peak force, in each position using the ground reaction forces. Reliability analysis was performed based on the intraclass correlation coefficient (ICC) and coefficient of variation (CV%); Spearman's rho was used to test the relationship between RFD and VJH. The results demonstrated that RFD[subscript 0-PF] was the only variable assumed to be reliable, demonstrating an ICC > 0.84 and CV < 8.5% in all positions, and significant correlations between RFD metrics and VJH were observed at SJ[subscript 70] and SJ[subscript PREF]. Some variables were underpowered due to the small sample size, as a limitation of the study.