Leishmaniasisis a disease caused by the protozoan parasite Leishmania sp. It is transmitted to humans by the bite of the blood sucking sand flies. Visceral Leishmaniasis (VL) has widely spread in the world including Yemen. In the present study, 60 BALB/c mice were classified into three groups: (A) 20 mice as control, (B) 20 mice infected by 2x10⁷ parasites for each animal through tail vein and (C) 20 mice treated with Aloe vera crude extract after infection with 2x10⁷ parasites. These animals were sacrificed at 20, 40, 60, 80 and 100 day post infection (p.i.). Various histopathological changes including: diffuse Kuppfer cells, hyperplasia with a heavy parasitic infiltration, portal and interlobular granuloma, necrosis and swelling in some hepatocytes, and sever fibrogenic changes appeared in infected mice. Vacuoles in the many hepatocytes were also observed at 60, 80 and 100 day p.i. Moreover, biochemical alteration were detected in the infected mice. Aloe vera plant illustrated a positive anti-leishmanial activity, where it has repaired some lesions, damage and decreased some destruction in liver tissues.