Background: Chemotherapy-induced hepatotoxicity can be mitigated by use of antioxidants, which may help the liver to recover its endogenous antioxidant mechanism. The objective of this study was to determine the effectiveness of sea buckthorn berry seed oil (SBO) in attenuating cyclophosphamide-induced changes in liver enzymes and liver histology in BALB/c mice. Methods: This experimental study was conducted in Physiology Department of Foundation University School of Health Sciences (FUSH), in collaboration with Pathology Department, FUSH and National Institute of Health, Islamabad from Jan 2018 to Jun 2019. Thirty healthy male BALB/c mice were divided into 3 groups of 10 each. Group-1 served as control. Group-2 received cyclophosphamide (25 mg/Kg body weight) intraperitoneally for 10 days. Group-3 was co-administered cyclophosphamide (same dose) with of sea buckthorn berry seed oil (40 mg/Kg body weight) orally for ten days. All animals were sacrificed on 11th day. Serum levels of liver enzymes as liver injury biomarkers were assayed. Liver histopathology was carried out for evidence of hepatic injury and recovery. Results: Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) increased significantly in Group-2 (p<0.05). In Group-3, the rise in hepatic injury serum markers was significantly less than Group-2 (p<0.05). Upon histological examination, Group-2 was grade 5 according to Kleiner’s scoring system for steatohepatitis, and had grade 2 sinusoidal dilatation on Rubbia-Brandt grading system. These changes were significantly less in Group-3 (p<0.05). Conclusion: Co-administration of SBO mitigated the CP-induced rise in hepatic injury biomarkers and sinusoidal injury. Pak J Physiol 2023;19(2):20–4