Toxoplasma gondii is an opportunistic parasite that infects a broad range of hosts including humans. The chronic latent phase of the disease manifests as intra-neuronal cerebral cysts tightly controlled by the host immune system. In immunocompromised patients, reactivation of cerebral toxoplasmosis can have severe neurological outcomes that may sometimes lead to death. Despite the efficient prophylactic and treatment measures taken against the rare reactivation of cerebral toxoplasmosis, many reports including several recent ones revealed the still occurrence of this spectrum of disease. We present the case of a 4 years-6 months old apparently immunocompetent child whose premortem clinical presentation and investigations were highly consistent with severe acute disseminated encephalomyelitis (ADEM). The patient received all appropriate medications with initial improvement followed by rapid deterioration and death. Postmortem brain autopsy revealed a wide reactivation of cerebral toxoplasmosis. This is a peculiar case presentation as such medical treatment for ADEM (i.e. steroids) may worsen the Toxoplasma infection with ominous consequences. This case highlights the importance to rule out the possibility of such infections in apparently immunocompetent hosts by performing the appropriate investigations to prevent complications.