Tumour necrosis factor alpha (TNF alpha) is an important cytokine in immune regulation and resistance to various micro-organisms. It provides signals to the target cells through two different receptors: TNFR1 and TNFR2. The present report reviews the role of TNF receptors (TNFRs) in the immune response against protozoan parasite infections of medical interest (Toxoplasma gondii, Leishmania major, Trypanosoma cruzi, Plasmodium spp.). TNF alpha has been regarded as a modulator cytokine in host defence against protozoans infections and recent findings on experimental gene-deficient mice have showed that TNF alpha/TNFRs pathway may be beneficial for host protection during these infections.