Abstract: The result presented in this research revealed the effect of oral administration of ethanolic leaf extract from Vernonia amygdalina as an anti-inflammatory as well as immunoregulatory agent in Swiss albino rats dosed with standard inoculums of Clostridium sporogenes (NCIB 532). Forty eight Swiss albino rats were used and divided into six groups. The first group was given normal saline, the second group was given 8 mL of the standard inoculum of the Clostridium sporogenes only and the third group was given the standard inoculum at the same time treated with the ethanolic leaf extract from Vernonia amygdalina. The other groups were given the booster inoculum of organism and booster shots after 3 and 5 days, respectively. Heamatological tests were carried out to determine the effect of the extract on the total white blood cell counts, packed cell volume, Neutrophil, Eosinophil and lymphocyte of the rats before, during and after infection. The result shows an increase in total WBC in the infected rat but the value reduces after treatment with Vernonia extract. Conversley, the PCV reduces in the in the untreated infected rat but the value became elevated after oral administration of the extract. Neutrophil values reduces during infection but the values became normal after treatment. Also urinalysis was carried out, both macroscopy and microscopy before, during and immediately after the infection in order to evaluate the immunomodulatory effects of the extract on the immune system of the infected rats. The rats were also weighed before, during and after infection, in which there was reduction in their weights during active infection in those that were dosed with the organism due to infection while those that were dosed with the Clostridium sporogenes and treated with leaf extract from Vernonia amygdalina and those given the extract only, showed an increase in their body weights respectively. This result showed that the ethanolic leaf extract from Vernonia amygdalina has immunomodulatory properties and it is able to inhibit proliferation of Clostridium sporogenes.