Ribeiro worked his way through the junior formulae, finishing fifth in the 1976 European Formula Two season. He financed his own entry into Formula One with March for the 1977 season, backed primarily by Caixa Econômica Federal and Souza Cruz. His tenure at March coincided with a period of internal disorganisation: team owner Max Mosley had hired four drivers simultaneously, and the team could not adequately support them all. Ribeiro's reputation suffered as a result.
In 1978 Ribeiro set up a privately owned F2 team to enter the European Formula Two season, a campaign dominated by the March factory outfit. His car carried the words "Jesus Saves" on its bodywork, matching livery he used on his Formula One cars and his helmet. The season produced one major highlight: a victory at the Nürburgring after pre-race favourites Bruno Giacomelli and Marc Surer retired. The win made Ribeiro the only Brazilian driver ever to win on the old 22.8-kilometre Nürburgring circuit.
In 1979 the Fittipaldi team offered Ribeiro two attempts to qualify a second car at the Canadian and United States Grands Prix, but the squad was focused entirely on former champion Emerson Fittipaldi and Ribeiro failed to make the grid on both occasions.
After his racing career wound down, Ribeiro took on the role of chaplain at Formula One events and became the driver of the FIA medical car, a position he held for many years. He joined the Brazil national football team as a pastor during the 1994 FIFA World Cup in the United States, later writing a book about their journey to the championship titled "Who Won the '94 World Cup?". In 1981 he had published an autobiographical book, "Mais Que Vencedor" (More Than A Winner), in which he referred to March owner Max Mosley as "Mack Mouse" and engineer Robin Herd as "Robin Hood".
Ribeiro's years driving the medical car produced several notable moments. At the 2000 Monaco Grand Prix he crashed the medical car at the Tabac corner before Saturday morning practice; passenger and FIA doctor Sid Watkins broke three ribs. At the 2002 Brazilian Grand Prix, on his farewell as medical car driver, Ribeiro opened the car door to check on Enrique Bernoldi following a crash, and Nick Heidfeld's Sauber struck the open door. Neither Ribeiro nor Heidfeld was injured.
Ribeiro's career illustrates the precarious position of pay drivers in the Formula One field during the late 1970s, when adequate car preparation was far from guaranteed. His Nürburgring F2 win remains a rare Brazilian achievement on a circuit celebrated for its difficulty. Outside racing he is remembered in Brazil for his pastoral work and his connection to the 1994 World Cup squad. A motorbike shop he owned in Brasilia at one point employed both Nelson Piquet and Roberto Moreno as young mechanics before either reached Formula One, giving Ribeiro the unusual distinction of having employed three Formula One drivers from the same business premises.