Paracetamol is a well-known hepatotoxic drug in acute overdose. Early assessment of the severity of acute paracetamol toxicity still a problem. Serum Cytokeratin 18-Asp396is a novel biomarker that reflects the degree of liver damage.This study was carried out to investigate that Cytokeratin 18-Asp396can represent an early and valuable predictor of pre-clinical and clinical acute paracetamol toxicity in humans.The clinical work was conducted at Minia PCC during the period from January, 1st, 2011 to December, 31th, 2015 where 127 adult patients with a history of paracetamol overdose from whom 84 patients had confirmed to have acute paracetamol toxicity, were received.All subjects were investigated for serum paracetamol level 4 hours post-ingestion and for liver function tests (ALT, AST, ALP andtotal bilirubin) and Cytokeratin 18-Asp396 at 4, 24, 36, and 48 hours post-ingestion.The results of the current study revealed that all investigated liver function tests including ALT, AST, ALP and bilirubin started to be increased with statistically significant values 24 hours post-ingestion, reached a peak after 36 hours, and started to decline after 48 hours. On the other hand it has been found that Cytokeratin 18-Asp396 values were increased significantly 4 hours post-ingestion, when compared to mean value of healthy volunteers, reached a peak after 36 hours, and started to decline after 48 hours. The results reflects the earlier effects of paracetamol toxicity on Cytokeratin 18-Asp396 serum level than the other measured liver function tests. Accordingly, Cytokeratin 18-Asp396 serum level could be considered a promising predictor for early diagnosis of pre-clinical and clinical acute paracetamol toxicity in humans. Further studies are recommended to assess its sensitivity and specificity as a predictor for early diagnosis of acute Paracetamol-induced hepatotoxicity.