Larsson made her debut for the Sweden Fed Cup team in 2005, eventually accumulating an overall win–loss record of 50–30.

She was awarded a wild card for a WTA event In Stockholm, beating Kristina Barrois in three sets before losing to Swedish No.

Towards the end of 2006, Larsson suffered an injured hamstring, made a came back in early 2007, and played mainly in the USA.

She returned to Fed Cup in 2007, losing to Maša Zec Peškirič and beating Vojislava Lukić and Naomi Cavaday, both ranked in the top 300, giving Sweden 9th place.

She was included in the 2009 Swedish Fed Cup team, along with Sofia Arvidsson, Sandra Roma and Ellen Allgurin.

In her next tournament in Acapulco, she was forced to retire with a knee injury while trailing top seed Ágnes Szávay one set down.

She started the year playing two $25k events in the United States; in the first tournament in Plantation, she made the final knocking out top seed Maret Ani en route.

She stayed unbeaten in singles and doubles throughout the four ties she played in Fed Cup, Sweden won promotion to the World Group II playoffs.

Larsson made her Grand Slam main-draw debut at French Open; in the first round she defeated Anastasija Sevastova before losing to Akgul Amanmuradova in the second.

Larsson then continued her form at the Slovenia Open, as she defeated eighth-seeded compatriot Sofia Arvidsson in the first round and Maria Elena Camerin in the second.

Then in the quarterfinals she caused a bigger upset, defeating third seed Anastasia Pavlyuchenkova and Ksenia Pervak to reach her first WTA Tour final.

She also lost in the second round of a $25k event in Stockholm before an improvement in form saw her make it to the semifinals of the Abierto Mexicano.

In the semifinals, she easily beat Sofia Arvidsson to advance to her second WTA Tour final, which she lost to eighth seed Polona Hercog, in straight sets.

Larsson then reached the semifinals of Sony Swedish Open in Båstad, losing to Mathilde Johansson.

[1] In the run up to the US Open, in Cincinnati, Larsson recorded a win over Marion Bartoli (ranked 11 at the time) before losing to Li Na.

Larsson began the season with a quarterfinal appearance in Auckland, beating Julia Görges in the second round.

Larsson made it to the final of the women's singles at the Swedish Open where she lost to top seed Serena Williams in straight sets, 4–6, 1–6.

Larsson began the year with a second-round finish in Auckland, losing to second seed Ana Ivanovic.