Lukas Runggaldier started his career with an FIS race (Gundersen HS 109/10 km) on January 22nd, 2005 in Planica in Slovenia with the 55th place. He got his first World Cup appearance on January 14, 2007 in a team competition in Val di Fiemme , where he came 11th. At the Junior World Championships in Tarvisio 2007 he came in 4th place with the team. In 2009 he took part in the Nordic World Ski Championships in Liberec and finished 26th in the Gundersen HS100 / 10 km. In 2011 at the Nordic World Ski Championships in Oslo he was 10th and 8th in the XXI. Winter Games in Vancouver he reached 16th place on the normal hill (HS106 / 10km) and 11th place on the large hill (HS140 / 10km). His best result so far is a 4th place on the normal hill (HS109 / 10km) in Seefeld.
In June 2020, Runggaldier announced the end of his career. He started at a total of 97 World Cup events, 13 competitions at Nordic World Ski Championships and nine competitions at the Olympic Winter Games.