We describe a case of a patient with a functional coma ,and give a systemic review of literature. Functional coma is an extremely rare disorder with only 21 described cases in the literature. The disease is linked to a conversion disorder or a dissociative disorder and is predominantly found in females. Predisposing factors are a history of sexual or physical abuse, psychiatric disorders, previous episodes of functional coma, and recent surgery with general anesthesia. Several clinical signs are suggestive for the diagnosis, however none of them is sufficiently sensitive or specific. Therefore, functional coma remains an exclusion diagnosis. Vital signs must be normal, just as a routine blood examination, an electroencephalogram and imaging of the central nervous system. The most important differential diagnosis are catatonia, factitious disorder, and malingering. Spontaneous recovery can be expected after a duration of about 45 minutes to 4 days.