In 2000, Barbalho was the President of the PMDB party and Senator when a wave of corruption allegations against him took national headlines, involving embezzlement of public funds at the Superintendência de Desenvolvimento da Amazônia (SUDAM - Superintendence for Amazon's Development) development agency and the Instituto Nacional de Colonização e Reforma Agrária (INCRA - National Institute for Colonization and Agrarian Reform).
Club Nacional de Football | Atlético Nacional | Instituto Superior Técnico | El Nacional | Museu Nacional d'Art de Catalunya | Distrito Nacional | Paseo de la Reforma | Liga Nacional de Fútbol de Guatemala | Jornal Nacional | Reforma | Museo Nacional Centro de Arte Reina Sofía | Estádio Nacional | Dirección de Inteligencia Nacional | Club Deportivo El Nacional | Radio Nacional de España | Liga Nacional de Fútbol Profesional de Honduras | Club Universidad Nacional | Instituto Tecnológico Autónomo de México | El Nacional (Caracas) | Club Nacional | C.D. Nacional | Partido Acción Nacional | Nacional Atlético Clube Sociedade Civil Ltda. | Instituto Politécnico Nacional | Instituto Pedro Nunes | Instituto Cervantes | Escola Nacional de Belas Artes | Nacional Records | Instituto Superior de Engenharia de Coimbra | Instituto Nacional de Bellas Artes y Literatura |