Aya auditioned in 2000 for the 4th Morning Musume & Heike Michiyo Protegee Audition, and was selected along with Sheki-Dol to become a part of what was later known as Hello! Project. It is a common misconception that Aya originally auditioned to be a part of Morning Musume, which she didn't.[1] After being chosen from that audition, Aya Matsuura began her solo career. In time she would become one of H!P's biggest acts.

Aside from a successful solo career, Aya Matsuura (nicknamed Ayaya), has also done numerous collaborations with other members of Hello! Project, including special, usually short lived groups Gomattou with Maki Goto and Miki Fujimoto; Nochiura Natsumi with Maki Goto and Natsumi Abe; and DEF.DIVA with Maki Goto, Natsumi Abe, and Rika Ishikawa. She's also done the "Folk Song" series which feature Yuko Nakazawa and other H!P artists, as well as Hello! Project's shuffle groups (Ayaya was placed in 3-nin Matsuri for 2001, Odoru 11 in 2002, Salt 5 in 2003, and the larger H!P All Stars in 2004).

Also, she has collaborated with Miki Fujimoto as a duo named GAM that debuted September of 2006. Their first single, "Thanks!" reached the #2 position on the Oricon.

Matsuura has appeared in many commercials for various companies; notably Pretz snack foods, Epson color printers, and Kirin beverages. Currently she also takes part and co-hosts the television show Utawara with other names in Japanese entertainment such as Johnny Jimusho's Jun Matsumoto.

Matsuura starred in the Japanese film Sukeban Deka: Codename = Asamiya Saki opposite Rika Ishikawa, released on September 30, 2006.

On October 9, 2006 both concerts she was supposed to hold that day were cancelled due to her not feeling well.[2] Soon several unsourced rumours emerged considering the possibility she might be suffering from Temporomandibular joint disorder.[3] Following the cancellation of the two concerts, Matsuura's management confirmed the rumours, reported the young idol had been taking painkillers to continue working and scheduled a press conference to discuss her condition.[4][5] On the following day Matsuura made a public statement on PBS apologizing to her fans and expressing her desire to get back to her singing career as soon as possible. Since her press conference, Matsuura has returned to her normal hosting duties on her weekly radio show, "Matsuura Aya no All Night Nippon" and has returned to singing in a limited capacity, as most recently demonstrated on her appearance on HEY! HEY! HEY! MUSIC CHAMP on October 23 2006.