Giardia lamblia is a common protozoan parasite infects humans and is the most common cause of waterborne outbreaks of diarrhoeal diseases. The present study examined the anti-giardiasis effective-ness of ginger as a natural product in the prevention and treatment of G. lamblia in infected mice. Male albino mice were divided into the following four groups: 1. Control uninfected untreated, 2. In-fected with Giardia cysts and untreated, 3. Prophylactic with ginger before infection, and 4. Treated with ginger after infection. The results showed that Ginger resulted in a complete eradication of Giar-dia cysts in the faeces after infection by day 12 in the protected group and day 10 in the treated group. IFN-γ levels were significantly decreased (p < 0.05) in the ginger-protected and ginger-treated groups, and IL-5 levels were elevated in both ginger groups. Histopathological observations of the ileum sup-port the immunological findings