Asante joined her first club Arsenal as a junior in 1998. She became a senior player in 2003/2004 season. Asante was part of the Arsenal team that won the quadruple in 2006/2007, collecting the UEFA Women’s Cup, FA Women’s National Premier League, FA Women’s Cup and the FA Women’s Premier League Cup. Asante was part of the Arsenal team that made history by being the first team outside Germany or Scandinavia to win the UEFA Women’s Cup. Asante is reported to have played exceptionally well in the final.

Asante played in the England Under 17 team. She also was a member and captain of the England Under 19s and played in the inaugural FIFA World Under 19 Championship in Canada in 2002. She won 11 international caps in all at this level. She was in the first call up for the England Under 21s in 2004, a month after her senior international début.

Asante made her senior international début as a substitute against Iceland in May 2004. Her first full international was against Northern Ireland in March 2005. She scored her first international goal in only her second full international which was against Norway in April 2005. This turned out to be the winning goal. Asante was named in England’s squad for Euro 2005.

On 3 July 2008, it was announced that Asante along with teammate Lianne Sanderson had joined Chelsea Ladies. Upon signing Asante said:

In 2009 Asante joined New Jersey–based WPS franchise Sky Blue FC. She helped the club win the inaugural WPS championship. On 6 May 2010 Asante was traded to the Saint Louis Athletica in return for India Trotter. When the Saint Louis Athletica folded on 27 May 2010, she was acquired by the Chicago Red Stars. She was subsequently traded to the Washington Freedom on 6 August 2010.

In December 2010 Asante returned for a second spell at Sky Blue FC, after Jim Gabarra, her coach at Washington Freedom, took the reins at Sky Blue. With the demise of WPS prior to the 2012 season, Asante signed a contract with Swedish club Kopparbergs/Göteborg FC. Her first match for Göteborg was back at Arsenal in the UEFA Women’s Champions League quarter final, a 3–1 first leg defeat. Asante played 41 league games for Göteborg over the two seasons, scoring nine goals. She won the Swedish Cup and the Swedish Super Cup with KGFC, before she signed for national champions LdB FC Malmö in October 2013. Due to a foot injury, it was not expected that Asante could play in Malmö’s looming Champions League fixture with holders VfL Wolfsburg. Asante, won several titles at FC Rosengård (formerly known as LdB Malmö) including the Damallsvenskan league 2014, 2015, the Swedish Cup (Svenska Cupen) 2016 and the Swedish Super Cup (Svenska Supercupen) 2016, 2017 and runners up in 2015. Anita has reached the quarter finals of Champions League three seasons with FCR.

Asante played in the 2011 World Cup and made her 50th senior international appearance in England’s 2–0 win over eventual champions Japan. Having been part of the English squad which reached the final of Euro 2009, Asante was confident of England’s chances ahead of Euro 2013. She was substituted at half time in England’s 3–0 defeat to France which sealed a first round elimination.

In June 2012 Asante was named in the 18–player Great Britain squad for the 2012 London Olympics. She played in all four games as Great Britain were beaten 2–0 by Canada in the last eight.

In 2015, the politically vocal Asante was “a glaring omission” from England’s squad for the 2015 World Cup in Canada. She had been the only English player to sign a petition against the controversial artificial turf used at the tournament.

On 7 June 2020, she signed for newly-promoted club Aston Villa, ahead of their maiden WSL campaign.