Chelsea's dramatic victory over Paris St Germain and Real's narrow aggregate win over Borussia Dortmund in the quarter-finals earned both a place in the last four of Europe's premier club competition, where they are joined by Barcelona's conquerors Atletico Madrid and holders Bayern Munich, who beat Manchester United.
Mourinho, 51, left Madrid in acrimonious circumstances in the summer - having led them to the 2011/12 La Liga title during his three-year reign - to rejoin Chelsea, who he led to two Premier League titles and an FA Cup victory during a successful spell from 2004 to 2007.
The Portuguese has faced Real four times in Europe as a manager, all during his time as Porto boss, and has never beaten them, losing three of the matches and drawing the other.
However, that draw - 1-1 in Madrid - came in a group game during Porto's run to winning Mourinho the first of his two Champions League titles in 2004.
Friday's draw could also see the rekindling of Mourinho's rivalry with his former Barcelona colleague Pep Guardiola, who now manages Bayern Munich.
The two worked together under Sir Bobby Robson at Barcelona, when Guardiola was a player and Mourinho assistant to the late former England and Newcastle boss.
However, the relationship between the two soured somewhat when Guardiola was Barcelona boss and Mourinho was in charge of Real.
Guardiola was uncharacteristically aggressive when talking about Mourinho's conduct in press conferences, while the Portuguese snapped at one reporter who pointed out that he had only won three of his 15 meetings with his Spanish rival.
Guardiola, though, was complimentary when talking about Chelsea as a potential opponent for his side this season.
"Chelsea have a manager with a lot of experience," he said. "They are an English team with many qualities and experienced players like Petr Cech, Branislav Ivanovic, John Terry and Frank Lampard."
Mourinho also has Champions League history with Bayern before they were managed by Guardiola.
His Inter Milan side beat Bayern 2-0 in the 2010 final.
In addition, Chelsea, then managed by Robert Di Matteo, secured a dramatic penalty-shootout victory over the German side in their own Allianz Arena stadium to claim their only Champions League crown to date in 2012.
Mourinho has a better record against Chelsea's other potential opponent.
In nine matches against Atletico Madrid as a manager - all as Real boss - he won eight, although the one defeat did come in last season's Copa del Rey final, which Diego Simeone's side won 2-1.
Mourinho was typically blunt when asked about the draw, saying: "It doesn't matter who we face."
Aside from Chelsea, the draw also presents a potential Madrid derby.
Real are regular competitors at this level, but surprise La Liga leaders Atletico are appearing in a European Cup semi-final for the first time in 40 years.
If the two Madrid sides are drawn together it would be the first meeting between the pair in Europe since 1959.
The first legs of the semi-finals will take place on April 22 or 23, with the return legs taking place a week later.
Watch the Champions League draw live on Sky Sports News at 11am on Friday. You can also follow it live on skysports.com and the Sky Sports apps plus Sky Sports News Radio will have all the reaction.