Neurological deficits associated with methylergometrine have been reported primarily as a result of reversible cerebral vasoconstriction syndromes (RCVS). RCVS are characterized by reversible multifocal vasoconstrictions of the cerebral arteries heralded by acute severe headache with or without neurological deficits. Here, we present the first case of suspected RCVS with transient limb myoclonus following the intravenous administration of methylergometrine during cesarean section. A 31-year-old woman who received slowly infused intravenous methylergometrine during a cesarean section suddenly reported severe occipital headache after 40 min, followed by apnea and unconsciousness for 8 min. A second administration of methylergometrine to treat the weakness of her uterine contractions resulted in a repeated loss of consciousness within minutes and the development of limb myoclonus. No abnormalities were detected by brain computerized tomography, magnetic resonance imaging, and electroencephalogram. She fully recovered spontaneously within 12 h. We consider that the transient limb myoclonus in our patient appeared as a result of RCVS caused by the intravenous administration of methylergometrine.