It is presented in this paper the results of a comparison in Electrical Power, between the National Laboratories of Germany: Physikalisch - Technischen Bundesanstalt (PTB), Argentina: Instituto Nacional de Tecnología Industrial (INTI), Brazil: Instituto Nacional de Metrología, Normalizaçao e Qualidade Industrial (INMETRO) and Uruguay: Usinas y Trasmisiones Eléctricas (UTE), carried out during 2004. The instrument used as traveling standard was a power standard belonging to the PTB. The results show equivalent values in the deviations as well as in the declared uncertainties, for all participants.