Born in Luanda, Portuguese Angola, Hélder first attracted attention as a Estoril player, moving to Benfica for the 1992–93 season where he would stay the following four and a half years, mainly as a starter.

[2] In November 1999, Hélder joined Newcastle United of the Premier League on loan for a fee of £500,000,[3] making 12 official appearances and scoring in a 2–2 away draw against Sunderland in the Tyne–Wear derby the following 6 February.

[4] In that season, the Spaniards went on to conquer their first league title, with the player failing to contribute in that competition; he subsequently returned to Depor, appearing very rarely in his last year, which ended in conquest of the Copa del Rey.

[5] For the 2002–03 campaign, aged 31, Hélder returned to Benfica,[6] playing there two more years (winning the Taça de Portugal in 2004)[2] and joining Paris Saint-Germain the following season, where he teamed up with compatriot Pauleta.

[15][16][17][18] Cristóvão's team collected more losses (21) than wins (15), conceding 64 times whilst scoring 59;[19] additionally, on 15 March 2016, he was suspended for 30 days after being sent off against Covilhã, which ended with a 2–2 home draw.

Cristóvão was named manager of Dunajská Streda on 6 January 2020, taking charge of the third-placed team of the Slovak Super Liga on a deal until 31 May.