On both occasions that they have walked off winners in the semi-finals, in 1996 and 2003, they went all the way to claim the coveted trophy but in 1997, 1998 and 2000 they fell at the second-last fence.
And now that they have seen to urgent domestic business against Grenoble with a morale boosting 52-24 victory at the weekend, Isitolo Maka believes the all-French semi-final could be a thriller.
We had to get the match against Grenoble out of the way - our win against them means we are now qualified for the French championship play-offs - but it was difficult not to think about the semi-final, said the former All Black No 8.
It is great for the French public to have two French teams in the semi-final and it means both sides will have a huge amount of support. It's also good for French rugby to have this kind of representation at the highest level.
It doesn't really matter who the opposition is. It is a semi-final and to be knocked out here would be devastating, though Biarritz were definitely the better team against Llanelli.
They have a very strong forward pack and that is also how they like to play against us, they will try to dominate that area of the game. They beat Llanelli up-front and they will want to do the same to us on Saturday.
But I'm confident in our players and in our strength in depth. We are definitely a team of 22 players and everyone who comes on to the pitch is desperate to give something extra to the game. I don't think we have had to play all out for 80 minutes yet this season - we often have peaks and troughs of intensity and concentration - but we will have to give it everything against Biarritz.
There is some rivalry between the two teams and there will certainly be some bite to the match. Every game is hard now but Biarritz is our biggest obstacle because it's our next one. If we lose, there's no point thinking about the final.
Fly-half Yann Delaigue, who scored 25 of Toulouse's points against Grenoble, added: A Heineken Cup semi-final is bound to be special because you don't play many of them in a lifetime.
It's going to be a huge occasion because the stadium will be full and whoever wins is in the final at Twickenham. Even last week we all had our heads in the semi-final but, if we lose, the adventure stops here so it doesn't matter whether we are playing another French team or anyone else - we have to win.
This is my last season at Toulouse - I am going to Castres next season - so I would like this season to end in the best possible way. As far as I'm concerned there is a huge desire to win the Heineken Cup again.
Biarritz's main strength is the way in which they adapt their game so well to whoever they are playing. Matches against Biarritz are always difficult. There is never one team who consistently beats the other - every season is equal where results are concerned so I think it's 50/50 for Saturday.
Dimitri Yachvili, the international scrum-half, declared: We don't care who the opposition is, this is a Heineken Cup semi-final and it's there to be won.
But Toulouse must be the favourites because they are the current Heineken Cup champions and the title holders always have a favourites tag.
Maybe we have nothing to lose but we will see about that on Saturday. Toulouse have many strengths - in fact they are a complete team. They are strong up front, they have speed behind, they are very well organised and they move the ball very quickly. It means we will have to be disciplined and take our game to them.
We have beaten Toulouse once this year - the return match is the week after the semi-final - and we know them well. But Toulouse are used to big occasions of semi-finals and finals, they have more experience.
But we are not asking ourselves all those types of questions. We are ready for the match and we have nothing else on our minds.
It's the Heineken Cup semi-final so the desire and motivation are there. It's at Bordeaux so we will have a lot of support and you will see a great deal of solidarity within the team.p>Joint coach Patrice Lagisquet has three injury worries ahead of the team selection. Captain and No 8 Thomas Lihvremont pulled out of his club's Championship match against Perpignan on Saturday morning with a back injury, centre John Isaac has hamstring trouble and prop ,b>Denis Avril is also a concern.We hope all three will be fit for selection but they are worries at the moment, said Lagisquet. We might be underdogs for Saturday's match but it is a Heineken Cup semi-final and we want to win it.
Toulouse are a formidable team, there is no way around that. And they are getting to that time of year when they grow as a team and get into their best form.
We are capable of posing them problems but to think that we will be able to dominate them up front like we did in December would be the biggest error we could make.
They are an intelligent team who are able to find the right solutions when needed. We too have to find the right arms with which to counter them.