Markus Gandler had a long career in international skiing, competing on the World Cup circuit for 16 years before retiring in 2000, and appearing at two Winter Olympic Games. He was on the team for the 1988 Calgary Games, but did not compete, and he missed the 1992 Winter Olympics with a serious injury. Gandler returned from that injury to win the silver medal in the 10 km at the 1998 Nagano Olympics. The following year, Gandler won a gold medal in the relay at the 1999 World Championships, skiing with Alois Stadlober, Mikhail Botwinov, and Christian Hoffmann. Despite his long career, Gandler had only one podium finish in the World Cup, a third at Canmore in 1990. In 1998 Gandler was given the Silver Medal for Meritorious Service to the Austrian Republic.
After his ski career he and Alois Stadlober started their own company to organize ski events and ski touring, Gandler & Stadlober Nordic Ski GmbH. Gandler also became a television commentator for the Austrian network ORF. Beginning in 2003 he also served as director of cross-country and biathlon for the Austrian Ski Federation. Although he did not compete at the 2006 Winter Olympics, Gandler was in charge of the Austrian Nordic team there, and was caught in the doping scandal in Torino, in which many of the Austrian team were considered to have used drugs after drug paraphernalia was found in their quarters. In May 2007 Gandler and multiple other Austrian team members were banned from future Olympic participation by the IOC.