There's critical need for risk predictors in long COVID. This metaâanalysis evaluates the evidence for an association between plasma lactate dehydrogenase (LDH) and long COVID and explores the contribution of LDH to symptoms persistent across the distinct postâacute sequelae of COVIDâ19 (PASC) domains. PubMed, EMBASE, Web of Science, and Google Scholar were searched for articles published up to 20 March 2023 for studies that reported data on LDH levels in COVIDâ19 survivors with and without PASC. Randomâeffect metaâanalysis was employed to estimate the standardized mean difference (SMD) with corresponding 95% confidence interval of each outcome. There were a total of 8289 study participants (3338 PASC vs. 4951 controls) from 46 studies. Our metaâanalysis compared to the controls showed a significant association between LDH elevation and RespâPASC [SMD = 1.07, 95%CI = 0.72, 1.41, p = 0.01] but not CardioâPASC [SMD = 1.79, 95%CI = â0.02, 3.61, p = 0.05], NeuroâPASC [SMD = 0.19, 95%CI = â0.24, 0.61, p = 0.40], and GastrointestinalâPASC [SMD = 0.45, 95%CI = â1.08, 1.98, p = 0.56]. This metaâanalysis suggests elevated LDH can be used for predicting RespâPASC, but not CardioâPASC, NeuroâPASC or gastrointestinalâPASC. Thus, elevated plasma LDH following COVID infection may be considered as a disease biomarker.