INTRODUCTION: Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a newly described form of encephalitis in children associated with prominent psychiatric and neurological  symptoms at onset. There are few cases described in Latin America with confirmed circulating anti-NMDAR antibodies. According to literature review this is the first case described in Ecuador. METHODS: Review of medical history and complementary studies. CASE DESCRIPTION: A nine-year-old-boy was admitted because of a head injury secondary to a transient loss of consciousness. Subsequently he developed progressive disorders of sleep/wake cycle, psychomotor excitability, choreoathetoid movements, orofacial dyskinesias, unintelligible speech, dysautonomic alterations and focal seizures. CT scan was unremarkable. DWI-MRI showed hyperintense bithalamic lesions. An EEG showed diffuse slowing with focal occipital spikes. Herpesvirus PCR and CSF cultures were negative. Paraneoplasic screening studies were also negative. A partial response to Methylprednisolone, Levetiracetam and Diazepam was seen.  Nevertheless, concomitant Immunoglobulin treatment significantly improved symptoms with independent return to his daily activities without extrapyramidal movements and seizure-free. During steroids weaning a relapse featuring psychomotor hyperactivity, orofacial dyskinesias, alternating sensory and visual hallucinations had been reversed with. IV methylprednisolone. Currently he is on multidisciplinary follow with almost total recover of his daily activities. Circulating anti-NMDA receptor antibodies were confirmed in CSF samples. CONCLUSIONS: Early recognition of the clinical manifestations of this condition will allow better recovery of acute symptoms, as well as a lower rate of sequelae. The identification of more cases in Latin America will also allow to define whether there are own characteristics of this disease in our population.