Aphanizomenon flose-aquae (AFA) is a fresh water unicellular blue green microalgae like Spirulina, but most AFA is harvested from the wild in volcanic regions leading to high levels of trace minerals. Aphanizomenon flos- aquae have been traditionally used for over 25 years for its health-enhancing properties. To investigate the possible anti-inflammatory role of Aphanizomenon flose-aquae, rats were injected with carrageenan. Results obtained in the present study showed that injection of rats with carrageenan led to significant decreases in red blood cells (RBCs) count, hemoglobin concentration (Hb) and hematocrit value (Hct) as compared to the control group. In contrast, the levels of white blood cells (WBCs) count, alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) activities were significantly increased; this was accompanied by histopathological and histochemical changes. Meanwhile, treatment of rats with AFA for 5 and twenty one days did not exhibit a toxic effect on the liver. Also, treatment of rats with AFA postcarrageenan injection exhibited anti-inflammatory activity and improved hematological parameters and liver function profile. In conclusion, using Aphanizomenon flos- aquae as a natural agent showed a strong anti-inflammatory role.