To evaluate the effect of methanolic extract of leaves of Ocimum gratissimum linn. on neutrophil phagocytic function. Were we used different concentrations (50,100,200μg/ml) of methanolic extract of Ocimum gratissimum was subjected to study its effect on different in-vitro methods of phagocytosis. such as neutrophil locomotion, chemotaxis, immunostimulant activity of phagocytosis of killed Candida albicans and qualitative Nitro Blue Tetrazolium test using human neutrophils. This preliminary study revealed that Ocimum gratissimum extract has stimulated chemotactic, phagocytic and intracellular killing potency of human neutrophils at the different concentration. From the results obtained it can be observed that the methanolic extract of Ocimum gratissimum leaves stimulates cell-mediated immune system by increasing neutrophil function phagocytic activity.