Context: Liver diseases are major causes of morbidity and mortality. Mesenchymal stem cells (MSCs) have immunomodulatory, anti-inflammatory, and antifibrotic effects, so they can be used in the treatment of liver diseases. MSCs co-cultured with diseased liver tissue improve the homing capacity, survival rate, and paracrine effects of the MSCs, as well as the ability to enhance liver function. Aims: This work aimed to study the therapeutic effect of MSCs versus MSCs co-cultured with liver tissue on carbon tetrachloride (CCl4)-induced hepatotoxicity in adult male albino rats. Settings and Design: Twenty adult male albino rats were divided into four equal groups; Group I (control group), Group II received CCl4 intraperitoneally (i.p.), Group III received CCl4 i.p. and then injected with MSCs intravenously (i.v.), and Group IV received CCl4 i.p. and then injected with co-cultured MSCs i.v. Materials and Methods: Finally, liver specimens were processed for light microscopy (LM) and electron microscopy (EM). Statistical analysis was carried out to assess histological scoring, area percentage of collagen fibers, number of glial fibrillary acidic protein-positive cells, and biochemical analysis of alanine aminotransferase and aspartate aminotransferase. Statistical Analysis Used: Statistical analysis of (histological scoring, area % of collagen fibers, and biochemical analysis) was done by using one-way analysis of variance (ANOVA) test using graphpad software (SanDiego, CA, USA). The means ± standard deviations were used for statistical analysis. Results: LM of Group II revealed loss of hepatic architecture and diffuse fibrosis with dilated congested blood vessels, bile ductular proliferation, and cellular infiltrations. Vacuolated cytoplasm with or without pyknotic nuclei was observed in addition to micro- and macro-steatosis. EM demonstrated disfigured hepatocytes with abnormal organelles surrounding atypical nucleus. Group III showed restoration of the normal liver architecture with greater extent in Group IV. Statistical analysis confirmed the microscopic findings. Conclusions: Co-cultured MSCs with diseased liver tissue augmented the therapeutic effects of MSCs in treating hepatotoxicity induced by CCl4 in adult male albino rats.