Mario Chaves was chief dental officer at the World Health Organization and a distinguished specialist in dental public health. He was born in Rio de Janeiro, Brazil on 12 July 1920 and trained at the University of Brazil, qualifying in dentistry and medicine, gaining a doctorate in dentistry and passing his habilitation in pathology and therapeutics in 1953. He first specialised in pharmacology at the University of Illinois, but later obtained a master of public health degree at Michigan University. He went on to posts at the Serviço Especial de Saúde Pública in Brazil, the Pan American Health Organization and the World Health Organization. At Escola Nacional de Saúde Pública Sergio Arouca/Oswaldo Cruz Foundation, he headed the department of health administration. At times he was the director of the Latin American Association of Dental Schools and the Pan American Federation of Associations of Medical Schools. Mario helped to make major advances in public health in Latin America, directing W K Kellogg Foundation financed projects and programmes in Brazil related to education, including technology centres for professional education in the area of health. He worked to create the Association of Faculties of Medicine, Dentistry and Nursing, and the Brazilian Association of Postgraduate Studies in Collective Health and UNIDA Network. At the Escola Nacional de Saúde Pública he financed continuing education programmes. He was one time chair of the Brazilian Academy of Dentistry. He authored several reference works in dentistry and medical education. His 1972 publication *Saúde e sistemas* (Rio de Janeiro, Fundação Getúlio Vargas, Serviço de Publicações) strongly influenced the teaching of health planning throughout Latin America. In the UK, he was a close confidant of Geoffrey Slack, professor of community and later public health dentistry at the London Hospital. He became a fellow of the Faculty of Dental Surgery in 1964. Mario Chaves died on 28 February 2015 in Rio de Janeiro. He was 96.