Top seeds Tigers will play fourth seeds Bath Rugby at the Walkers Stadium at 3pm on Saturday, May 9.
Second seeds Harlequins will play third seeds London Irish at the Twickenham Stoop at 5.30pm, also on Saturday 9th May.
In addition to the semi-final qualifiers, Sale Sharks and Gloucester Rugby will also play in the Heineken Cup next season after finishing fifth and sixth respectively.
The seventh English place in the Heineken Cup will be allocated to either Northampton Saints, Saracens or Worcester Warriors should they win the European Challenge Cup.
Should Bourgoin win the European Challenge Cup, London Wasps will take the seventh and final Heineken Cup qualification place due to their seventh place finish in the Guinness Premiership.