[2] Mendes is among the most influential football agents in the world, with clients including Cristiano Ronaldo, David de Gea, José Mourinho, Diego Costa, James Rodríguez and João Félix.

Hugo Viana's move from Sporting CP to Newcastle United in the Premier League for around €12 million in 2002 was his first major international transfer.

[11][12] Part of Mendes' success was ostensibly based on his frequent presence at football schools and youth teams throughout Portugal, spotting and signing young players, as he did with Cristiano Ronaldo and Ricardo Quaresma.

[13] It has been reported that Mendes came to physical blows at the Portela Airport in Lisbon with Luís Figo's agent, José Veiga, whose influence he was gradually supplanting at this time.

[13] Mendes' association with Anderson reflected the connections he established in South America, in which he worked closely with Pini Zahavi.

[11] In August 2010, football agent Gonçalo Reis complained that he had been left on the sidelines when Bebé, a player he represented, was transferred to Manchester United from Vitória de Guimarães.

"[21] In July 2010, Reis arranged Bebé's move to Vitória as a free agent from Estrela da Amadora in the semi-professional Portuguese third division after the cancellation of the player's contract due to the club's inability to pay his wages.

Manchester United signed Bebé for a reported fee of £7.4 million five weeks later, when he had played just six pre-season friendlies for Vitória.

[26] He had reportedly been recommended to the club by Carlos Queiroz, who had two spells as assistant manager at Manchester United and who at that time was coach of the Portugal national team.

[27] On 22 September 2014, an investigation by The Guardian implicated Jorge Mendes alongside ex-Manchester United and Chelsea chief executive Peter Kenyon in breaching FIFA regulations regarding third-party ownership and conflict of interest in player representation, buying player rights through companies based in Jersey and Ireland.

[31] Along with the help of team general manager Andrea Butti and sporting director Kevin Thelwell, 12 players were signed within six weeks during the 2016 summer transfer window.