Plumieride, an iridoid glucoside isolated from Plumieria acutifolia leaves was investigated for its immunostimulatory activity on humoral, cell mediated and intracellular cytokine levels in sensitized and unsensitised balb/c mice. Plumieride restores the suppressed cell mediated, humoral immune response and also enhances the release of TNF- α, IFN-γ, and IL-2 (Th-1) in immune compromised cyclosporine and cyclophosphamide treated balb/c mice. It does not stimulate the IL-4 (Th-2) expression. Plumieride demonstrates significant augmentation of Th-1 response in immunosuppressed balb/c mice. Results of the present study suggested that plumieride can be developed as an immunostimulatory adjuvant to treat the immune suppression in various disease condition(s).