Broilers are frequently infected with Escherichia coli (E.Coli) bacteria, which often leads to the emergence of many diseases and high economic losses. Hence, the present study was performed to assess the comparative e cacy of dietary rosemary and fenugreek, under E.Coli-infection in broilers, via evaluation of growth performance, biochemical indices, immunological response and histo-morphological changes.Eighty Cobb broilers were allotted to four equal groups (n=20 chicks/group); control non-infected (CN), control infected (CI), rosemary infected (RI) and fenugreek infected (FI) groups. RI and FI groups showed a signi cant elevation in their body weight and body weight gain compared with CI group. Moreover, both groups revealed a signi cant decline in serum aspartate and alanine aminotransferase activities, as well as uric acid and creatinine levels. Signi cant decreases of total antioxidant capacity, catalase and superoxide dismutase activities were noted among CI chicks. Moreover, distinctly higher levels were evident in both RI and FI groups. Immunomodulatory markers assessment showed a signi cant increase in immunoglobulin G with a signi cant decline in interleukin-6 level in both RI and FI groups, with the lowest IL-6 value within FI group. Histopathological evaluations focused on the deleterious effect associated with E-Coli infection of broilers' liver, kidney, intestine, spleen, bursa of fabricius, and thymus. A partial histological improvement was noticed among RI group, and nearly normal tissues were recorded in FI group. Overall, these ndings suggest the ability of fenugreek to mitigate the adverse effects of E.Coli-infection on broiler performance and tissue pictures, through improvement of the chicken general health condition.