It began airing on TF1 on June 19, 2009 and continue to air until September 25, 2009, lasting 99 days, and is presented by Benjamin Castaldi, who presented Loft Story and the first two seasons of Secret Story.

The contestants are kept locked away for 14 weeks in a house, called "La Maison des Secrets" (the House of Secrets) measuring 1600m² styled on the UK Big Brother house including a swimming pool, Jacuzzi, a lounge, a big bedroom divided by a shattered glass, bathroom with showers and 5 secrets room which are the Crystal room, Love Cave, Museum of Secrets, White Room and Bedsit (like Big Brother 5 UK).

All of the rooms are installed with cameras, (except the toilet due to a law imposed by the Conseil Supérieur de l'audiovisuel).

The Voice speaks to the contestants at times, and acts like "Big Brother" in other countries.

Each Tuesday, 2 contestants are nominated and put up against the public vote, one housemate will be evicted every Friday.

The third series of Secret story launched on the 19th of June 2009 with eighteen housemates entering the house.

On Day 8 a new housemate previously dubbed as Mystery Candidate, Martin, entered the house.

Angie was again nominated in week ten against Sabrina and was evicted on day 71 after receiving 44% of the vote to save.

She participated in the first Portuguese version, where she was the 4th housemate evicted on Day 21.

Dider is also a transvestite who uses the name Alicia for his female alias.

In an unknown episode he decided to talk behind his friends back to win 3 000 euros.

Francois-Xavier was first nominated for eviction in round seven against Jonathan and Romain and barely survived.

On finale night, he was named runner up, losing to Emilie.

Kevin was evicted on day 78 after receiving 39% of the vote to stay.

Martin entered the house on day 8 and was nominated for eviction along with Jonathan following the second round of nominations and was evicted on day 15 after receiving only 32% of the vote.

In week three he was nominated by La Voix for revealing his secret to Jonathan and faced the public vote alone.

Romain survived his first nomination having garnered 59% of the vote to stay.

Romain was nominated again in week seven against Francois-Xavier and Jonathan and was evicted on day 50 after receiving only 29% of the vote to stay.

Before leaving, he proposed to Angie, wishing that she continued the game as far as possible.

Rachel Legrain-Trapani, participating in the show under the name Rosa, entered the house on Day 1.

Nominations follow a different formula than is typical of the Big Brother franchise.