This study was conducted to evaluate the possible protective impact of Chlorella vulgaris (C. vulgaris) on liver tissues of adult male albino rats intoxicated with deltamethrin (DLM). Thirty-two adult rats were divided into four equal groups. The control group was orally administered 0.5 mL normal saline once daily for eight weeks. The second (Chlorella group (CV)) and third (Deltamethrin group (DLM)) groups, were orally received 50 mg C. vulgaris powder/kg BW and deltamethrin 3 mg/kg BW once daily for eight weeks respectively, while the fourth group was orally received CV and DLM together, with the same previous mentioned doses and duration. DLM treated group induced a significant elevation of serum alanine aminotransferase(ALT) and alkaline phosphatase (ALP) activities. Liver oxidant/antioxidant status was altered due to DLM intoxication. Meanwhile, C. vulgaris powdernormalized the changes of ALT and ALP activities. Moreover, it improved oxidant/antioxidant status of the liver related to DLM intoxication. C. vulgaris supplementation could overcome the DLM-induced hepatotoxicity through eliminating the oxidative tissue injuries.