Ethanolic extracts of T. cordifolia and C. asiatica were evaluated for immunostimulatory effect inmice against sheep RBCs as antigen by three models viz. delayed type hypersensitivity reaction,percent change in neutrophil count and haemagglutination titre. Immunostimulatory effect in thepresence of immunosuppressant agent, cyclophosphamide (100 mg/kg, i.p.) was alsoinvestigated. T. cordifolia and C. asiatica significantly (p < 0.001, p < 0.05 respectively) enhancedfoot pad thickness when measured after 24 hours of sheep RBC antigen challenge. Both the plantmaterials increased foot pad thickness even after being subjected to immunosuppressantexposure. T. cordifolia revealed enhanced neutrophil counts, while C. asiatica had no significanteffect on neutrophil counts. T. cordifolia exhibited significantly (P < 0.01) elevated neutrophillevels even in the presence of cyclophosphamide administration. Both the plants exhibitedhumoral antibody response, as haemagglutination titre values were significantly high ascompared to control. T. cordifolia and C. asiatica could combat immunosuppressant effect ofcyclophosphamide (P < 0.01). This suggests that T. cordifolia and C. asiatica can be regarded asbiological response modifiers and can be utilized for the development of immunostimulatingagent among plant sources.