Myhrer made his World Cup debut in January 2004 and his first victory came at Beaver Creek, Colorado, in December 2006. Myhrer represented Sweden at the 2006 Winter Olympics and tied for fourth place in the slalom, only 0.03 s from third. At the 2010 Olympics he was tenth after the first run of the slalom at Whistler, then had the fastest time in the second and won the bronze medal. In 2018, Myhrer won the Olympic slalom competition after both main favourites had failed to finish. In addition to four Olympics, Myhrer has competed in nine World Championships.