Vaccination is a cost effective means of disease prevention that has already prevented millions of people from death. Recent advances have led to the development of new and promising vaccine strategies, which include development of polysaccharide, subunit/ recombinant vaccines. These vaccines have better safety profile but poor immunogenecity, which require immunopotentiators as adjuvants. Currently many immunomodulators including biological, synthetic and naturals are under evaluation as safer and effective immuno-adjuvants. Hence it requires safer and effective vaccine adjuvants. Botanical immunomodulators are under evaluation as newer and safer adjuvants. Withania somnifera (WS) is a immunomodulator from natural sources which is also mentioned in Rasayana. This present study is an attempt to evualate Immunoadjuvant activity of WS in an experimental system using DPT vaccine and flow cytometry. The results suggests modulatory effect of WS on CD4 and CD8 percentages resulting in significantly higher anti-diptheria antibody titres coupled with protection even with lower imuunogenic doses of DPT vaccine.