The efficacy of the methanolic fraction (MF) of Tribulus terrestris fruit extract on mercury intoxicated mice, Mus musculus has been studied. At a median-lethal dose of mercuric chloride (12.9 mg/kg body wt.) administration an enhanced level of glutamate oxaloacete transaminase (GOT), glutamate pyruvate transminase (GPT) and simultaneously decreased level of acid phosphatase (ACP) and alkaline phosphatase (ALT) activities were noticed in the liver. Due to the mercury toxicity the liver cells are damaged to cause the alterations in their enzymes. During the recovery period, all the enzymological parameters are restored to reach near normal level. The result suggested that the oral administration of MF of T. terrestris fruit extract has (6 mg/kg body wt.) provided protection against the mercuric chloride induced hepatic damage in the mice, M. musculus.