Introduction: Chest compression release velocity (CCRV) during chest compression (CC) recoil is understudied in pediatrics. Our objective was to characterize CCRV during pediatric in hospital cardiac arrest (IHCA). Methods: Using the PediRES-Q multicenter prospective observational cohort from 2015 to 2021, we analyzed patients <18 years who received ≥ 20 minutes of CPR with quantitative CPR metrics (ZOLL R Series) across 30 sites. Median and Interquartile Range (IQR) CCRV, measured by pad integrated accelerometers, was defined as maximum velocity during CC recoil. CCRV was calculated for each CC and compared between 3 age groups. Initial (min 0-3), early (min 5-8), and late (min 15-20) periods of CPR were compared when metrics were available for all stages. Wilcoxon rank sum was used for comparisons. Results: Of 308 events with CC metric data and ≥ 20 min duration there were 106 (34%) <1 yo, 114 (37%) 1<8 yo, and 88 (29%) 8<18 yo. Median [IQR] duration was 43 [31, 58] min. Median CCRV for <1 yo: 152 [125, 179] mm/s; 1<8 yo: 213 [177, 261] mm/s; and 8<18 yo: 397 [294, 388] mm/s. Difference in CCRV between age groups was significant (p<0.0001) with CCRV increasing as age increased. 185 events had complete CC metric data during initial (min 0-3), early (min 5-8), and late (min 15-20) periods of CPR. There was no significant difference in CCRV over time: initial 222 [159, 329] mm/sec; early 218 [154, 322] mm/sec; late 219 [163, 321] mm/sec. Similar lack of difference over time was demonstrated between the 3 age groups: <1 yo initial 151 [113, 191] mm/sec; early 149 [119, 191] mm/sec; late 160 [127, 213] mm/sec; 1<8 yo initial 222 [177, 277] mm/sec; early 237 [186, 276] mm/sec; late: 220 [185, 256] mm/sec; and 8<18 yo initial 376 [270, 524] mm/sec; early 395 [277, 441] mm/sec; late 381 [280, 468] mm/sec. Conclusions: We characterized CCRV during pediatric IHCA as a metric of CPR performance related to chest recoil. CCRV was significantly slower for <1 yo, faster for 1 to <8 yo, and fastest for 8 to <18 yo. Surprisingly, CCRV was not different over time (initial, early, late CPR periods). These findings suggest differences in CCRV related to patient age but do not demonstrate changes in CCRV over time in the first 20 minutes of CPR.