She started her career in Randesund IL, a district club in Kristiansand. In 2003, Mykjåland played with Amazon Grimstad and played there until she went on to Røa in September 2005. Mykjåland was Røa's top scorer in 2007 with 11 goals.
She quickly became one of the league's top talents, and has also managed to establish herself on the Norwegian National senior squad, having been called up to both the 2007 Women's World Cup as well as the 2008 Summer Olympics held in Beijing, China.
On 21 October 2008 Lene Mykjåland and four other Røa players — Marie Knutsen, Guro Knutsen, Marit Fiane Christensen and Siri Nordby — made headlines when they announced in a press release that they would not be returning to the national team due to issues the five had with the national team leadership. While the press statement never mentioned coach Bjarne Berntsen's name, it was assumed that he was instrumental in their decision to retire from the team. The retirement, which came off in many newspapers as a boycott, created widespread media attention. When Eli Landsem took over the national team after the 2009 European Championship, they ended their boycott and made themselves available again for the national team. On 15 January 2010, Mykjåland played her first game for Norway since the boycott in a 1–1 draw against England. In 2011, Mykjåland was included in the squad that was going to play in the 2011 Women's World Cup.
The Washington Freedom of Women's Professional Soccer announced on 23 December 2009, that they had signed Mykjåland, and she joined the team on 1 April 2010. After one season in America, she returned to Norway and signed a two-year contract with former team Røa.
Statistics accurate as of match played 30 October 2016