The immune system helps in eliminating toxic or allergenic substances that enter through mucosal surfaces. The immune system's ability to mobilize a response to an invading pathogen, toxin or allergen is its ability to distinguish self from non-self. This investigation aimed to study the immunomodulatory efficacy of phyllanthus emblica and costus speciosus aqueous extracts for immunosuppressive rats. Forty two mature male albino rats weighing 150-200 g were used in this work. Rats were divided into 6 equal groups (n=7 rats); one group kept as a control negative, while the rest five groups were once injected intraperitoneally with a single dose (200 mg/kg body weight) of cyclophosphamide for immunosupprission, then devided to five equal groups, one of them left as control positive group (C +ve) while the rest four  groups orally ingested with two doses (250 and 500 mg/kg) of phyllanthus emblica and costus speciosus aqueous extracts for each of them. At the end of experimental period (45 days), blood samples were collected and CD4, CD8, CD16 and CD19 were analyzed by flow cytometric analysis. IgM, IgA and IgG were determined using indirect enzyme-linked immunosorbent assay (ELISA). The levels of serum albumin and globulin were determined. The obtained results concluded that phyllanthus emblica and costus speciosus enhanced immunomodulatory efficacy by increasing blood levels of CD4, CD8, CD16, CD19, IgM and IgG, moreover, increasing serum levels of albumin and globulins. The group of costus speciosus at a dose of 500 mg/kg. b.wt., declaired the best significant results to boost immunity compared to all experimental groups. The present investigation revealed that Phyllanthus emblica and costus speciosus aqueous extracts possess immunomodulatory efficacy with regard to immunosuppressive animals.