Psychogenic nonepileptic seizures (NES) are commonly encountered in clinical practice, and they may pose difficult diagnostic problems. For appropriate evaluation and treatment of NES, a multidisciplinary team approach is needed; typically, a neurologist with expertise in epilepsy, a psychologist or psychiatrist, and a support staff should be involved. Psychogenic NES have no single initial clinical manifestation, and various etiologic factors may contribute to their development. Of importance, psychogenic NES are "real" seizures that may be as disabling as epileptic seizures. Most often, they occur on a subconscious level, and the patient may have no control over their occurrence. Precipitation or termination of a habitual seizure during video-electroencephalographic monitoring has often been used to distinguish NES from epileptic seizures, but the results can sometimes be misleading. Numerous additional diagnostic techniques can be used to assist in making the diagnosis. Treatment is based on the type of psychiatric disorder present. Favorable prognostic factors include being female and having an independent lifestyle, normal electroencephalographic findings, higher intelligence, and no prior psychotherapy.