Abstract: Objective: In this study, the immunopotency of dried coriander seed (Cr), turmeric (Tu) and thyme (Th) powders feed additives in broilers was investigated. Methodology: Three hundred, day old broiler chicks were divided into 5 groups, each of 3 replicate and kept for a period of 35 days. A basal diet was used to which Cr, Tu and Th were added either solely at level of 0.75% or in mixture (Mx), while control fed basal diet (C). Haemagglutinating Inhibiting (HI) antibody titre against Newcastle Disease (ND) was measured in sera of all birds. By the end of the experimental period, three birds from each replicate were weighed and killed then bursa (Br), thymus (Thy) and spleen (Sp) were extracted to calculate weight indices and fixed in formol buffer for morphometric measurements. Results: The HI titres were higher (p<0.05) in Cr and Tu compared with others. The Br, Thy and Sp weight indices were higher (p<0.05) in all groups than C, while those of Tu, Th and Mx groups were higher (p<0.05) than Cr group. The morphometric measurements were higher (p<0.05) in all treated groups compared to C, while values of Tu were higher (p<0.05) than Th and Cr groups. Conclusion: Dried Cr and Tu feed additives had an immunomodulatory effect in broilers.