Anti typhoid properties of methanol leaves extract of Acacia nilotica was investigated. The phytochemical screenings for detection of the presence of bioactive constituents were carried out. Among other parameters investigated include LD50 of the leaves extract, inoculation of mice with Salmonella typhi parasites treating them with leave extract of Acacia nilotica followed by widal tests. The phytochemical screening of the methanol leave extract of Acacia nilotica revealed the presence of alkaloid, anthraquinone, carbohydrates, cardiac glycosides, flavonoid, saponin, tannins and terpens. The leaves extract of Acacia nilotica has possess some acute toxicity effect on animals (mice) at a dose of (LD50) 288.5mg/kg. The plant extract produced inhibitory activities against Salmonella typhi. It is interesting to note the widal test titer valve was found to be 140 for the treated group while the untreated group had titer value of 1160, suggesting that the plant leaves extract was effective as anti typhoid agent against salmonella typhi on mice infected with typhoid parasites. The extract demonstrated high activity against Salmonella typhi, bacterial typhoid causing agent.