Costa became a professional cyclist at Benfica in 2007, and switched to Caisse d'Epargne in 2009.
In 2009, Costa won the Four Days of Dunkirk followed by a win on stage 8 of the 2010 Tour de Suisse.

In 2010, Costa was involved with an altercation with Carlos Barredo at the end of Stage 6 of the Tour de France, with Barredo removing his front wheel and attempting to club Costa with it before both riders lobbed blows at each other.
Both were fined 300 francs for the incident.

At the Portuguese national championships in June 2010 Costa and his brother Mário tested positive for the banned substance methylhexanamine, which they claimed to have ingested inadvertently due to a tainted food supplement.
Further testing proved that to be the case, and he re-signed with his former team, then known as Movistar Team, in April 2011 after five months of suspension.
Costa became a professional cyclist at Benfica in 2007, and switched to Caisse d'Epargne in 2009. In 2009, Costa won the Four Days of Dunkirk followed by a win on stage 8 of the 2010 Tour de Suisse.
In 2010, Costa was involved with an altercation with Carlos Barredo at the end of Stage 6 of the Tour de France, with Barredo removing his front wheel and attempting to club Costa with it before both riders lobbed blows at each other. Both were fined 300 francs for the incident.
At the Portuguese national championships in June 2010 Costa and his brother Mário tested positive for the banned substance methylhexanamine, which they claimed to have ingested inadvertently due to a tainted food supplement. Further testing proved that to be the case, and he re-signed with his former team, then known as Movistar Team, in April 2011 after five months of suspension.
Rui Costa (cyclist)