Nitric oxide (NO) is involved in the clearance of several types of bacteria, viruses and parasites. Although the roles of NO and CD8+ T cells in the immune response to malaria have been extensively studied, their actual contributions during the blood stages of malaria infection remain unclear.;;In this work, we corroborate that serum NO levels are not associated with the in vivo elimination of the blood stages of Plasmodium chabaudi AS. In addition, we show that CD8+ T cells exhibit increased apoptosis and up regulate the expression of TNF-α mRNA on day 4 post-infection and IFN-γ and IL-10 mRNA on day 11 post-infection. Interestingly, only the levels of IFN-γ and IL-10 expression are affected when iNOS is inhibited with aminoguanidine (AG), suggesting that NO could... be involved in the activation of CD8+ T cells during the blood stages of plasmodium infection.