Aim: To study the immunoadjuvant potential of Azadirachta indica against different vaccine antigens (Rabies, hepatitis and DPT). Methodology: In order to study the IgG antibody titre of hepatitis B surface antigen (HBsAg), diphtheria-pertussis-tetanus (DPT) and rabies vaccine antigen with variable doses of aqueous extract of Azadirachta indica and also estimate the human blood counts (i.e. lymphocytes, monocytes and granulocytes) were evaluated. Results: Azadirachta indica has anti-HBsAg, anti-DPT and anti-rabies antibody IgG titre as compared to standard vaccine. In addition, vaccines containing Azadirachta indica increased the number of lymphocytes, monocytes and granulocytes count in whole blood as compared to standard vaccine. Conclusion: The study presents evidence that Azadirachta indica is a plant based adjuvant candidate of choice over commercial vaccine which is available in the market and improving as well as maintaining the improved immune status against HBsAg, DPT and rabies vaccine antigen.