Nigel Davies' side topped their pool in this season's Amlin Challenge Cup, with six wins from six matches, clinching this home quarter final against the Basque side.
The teams last met back in January 2010, when Gloucester triumphed by 23 points to 8 in a Heineken Cup pool match at Kingsholm. Another tough encounter beckons on Thursday evening.
The last two home games have been seen crowds in excess of 14,500 and another big crowd will be a huge boost to Nigel Davies and the squad.
Tickets are still available and the Ticket Office at Kingsholm will be open from 10am on Easter Monday until 3pm for personal customers and telephone callers on 0871 871 8781.
Alternatively, you can purchase online by clicking HERE