Aims & Objectives: Pediatric intensive care unit (PICU) admission is a life-threatening event placing survivors at risk for posttraumatic stress disorder (PTSD). This systematic review sought to describe the prevalence of PTSD in PICU survivors and analyze potential risk-factors driving variation in prevalence estimates. Methods: MEDLINE, Embase, CINAHL, and CENTRAL databases were searched from 2000 to August 2022, no language restrictions. Stage one screening of abstract and full text sought to identify studies evaluating PICU survivors post-discharge. Stage two screening identified specific studies reporting on incidence or prevalence of PTSD and/or risk factors. Given the large number of citations, we utilized a validated hybrid model of machine learning and crowdsourcing, recruiting a global community at the WFPICCS 2022 meeting. Random effects meta-analysis calculated pooled PTSD prevalence and evaluated subgroup differences. Results: From the original 15950 citations, 22 met criteria with a median cohort size 59 (IQR 49-76). PTSD prevalence ranged from 3% to 37%, with 529 of the total 1898 survivors reported as having PTSD (I2= 72%). Study factors impacting PTSD variability included months assessed post-PICU (p<0.01) and instrument utilized (n=9, range 4-27%; p=0.03). Patient diagnosis mattered, with lower PTSD (8%) in post-operative cardiac patients (p<0.01). Interestingly, PICU length of stay did not impact PTSD, although heterogeneity was high. Conclusions: 1 in 4 PICU survivors (29%) developed PTSD six months post-PICU. We identified numerous population and study design factors that influence prevalence and heterogeneity. This review demonstrates the need for more standardization in post-PICU PTSD clinical application and research. Trial registration: PROSPERO, CRD42022348997 Keywords: PTSD, Systematic Review, Post PICU