INTRODUCTION. The Guillan-Barre syndrome is the most frequent case of acute flacid paralysis in children. The diagnostic criteria differ according to the demyelinating or axonal variant and the prevalence by geographical area. The electro-myographic study permits identifying variants, evaluating the prognosis and predicting the evolution, is in addition an objective tool for the monitoring. AIM. To describe the electromyographic characteristics of the Guillain-Barre syndrome evaluated in hospital and its classification by physiopathological pattern. PATIENTS AND METHODS. All the cases diagnosed between 2005 and 2012 are included. Studies of motor and sensitive nervous conduction and F waves in 14 girls and 11 boys between 1 and 13 years of age. RESULTS. 19 cases of acute inflammatory demyelinating polyneuropathy (AIDP) and five of acute motor axonal neuropathy (AMAN) were diagnosed. The electromyogram was performed between 1 and 30 days after the beginning of symptoms. In AIDP cases, multifocal demyelination, four of them with the preserved sural and 13 with alteration and absence of F wave were objectified. In the cases of AMAN, four had low amplitude potential and in one of them they were not evoked. CONCLUSIONS. The demyelinating form of the illness is the most frequent although the high number of AMAN cases stands out, probably related to the population object of study. The evolution was favorable in three cases of motor axonal neuropathy and in 15 accute demyelinating polyneuropathy. In four cases the symptoms became chronic; three of them with persistent demyelination a similar occurrence in other studies with children.