While at the club, Cissokho settled into his role as a left back with his coaches describing him as a player with great potential.
He was, subsequently, promoted to the senior team for the 2007–08 season and assigned the number 3 shirt by manager Alain Ravera.
After positive displays for Vitória de Setúbal, on 9 January 2009, the defending champions Porto announced the club had acquired 60% of Cissokho's rights for a modest fee of €300,000.
[11] Upon his arrival, Cissokho was given the number 28 shirt and immediately inserted into the starting lineup by manager Jesualdo Ferreira making his debut 17 January in a Taça da Liga match against Académica de Coimbra.
[3] The unbeaten streak led to the club winning its fourth consecutive league title and giving Cissokho his first major honour.
In the UEFA Champions League, Cissokho made his debut on 24 February 2009 in the opening leg of the team's first knockout round tie against Spanish club Atlético Madrid.
[13][14][15] In the quarter-finals, Porto faced English club Manchester United and Cissokho was tasked with the objective of containing the 2008 FIFA World Player of the Year Cristiano Ronaldo.
[16] Despite putting up a strong effort in the first leg, which ended 2–2 at Old Trafford, Porto were defeated 3–2 on aggregate after losing 1–0 at the Estádio do Dragão.
As the parties failed to reach an agreement, Milan general manager Adriano Galliani announced the deal was cancelled.
[25] Cissokho was immediately inserted to the starting 11 by manager Claude Puel, replacing the Italian international Fabio Grosso, who departed for Juventus.
[26] On 26 September 2009, Cissokho assisted on the equalizing goal, scored by Yannis Tafer, in the 52nd minute of a league match against Toulouse.
[33] He was ruled out for six weeks after an injury which caused him to be taken off after ten minutes in the League Cup match against Notts County.
He made his first assist for Luis Suárez's second goal in a 4–1 victory over West Bromwich Albion, via an inadvertent rebound.
[37] On 5 August 2015, Cissokho returned to Portuguese club Porto on a season-long loan, rejoining the side after a short spell in 2009.
[38] He was eventually issued squad number 43 and went straight into the starting 11 against fellow relegation candidates Sunderland in a 3–1 defeat on 2 January 2016.
On 14 January 2017, Olympiacos officially announced Cissokho had joined the club on a six-month loan from Aston Villa, with the option of permanently purchasing the player during the summer 2017 transfer window, subject to satisfactory performances.
[46] Due to hovering in the second division with Gueugnon, Cissokho never earned call-ups with any of France's international youth teams.
[47] On 3 October 2009, Cissokho announced he would be open to representing the France national team, but his main focus was currently with his new club.
On 5 November 2009, Cissokho was included in the France squad by coach Raymond Domenech for the team's 2010 FIFA World Cup qualification playoff round tie against the Republic of Ireland to serve as backup to Patrice Evra.