In 2001 Thorkildsen moved to Oslo and started competing for the club SK Vidar under coach Åsmund Martinsen, a former javelin thrower who won the bronze medal at the 1994 Norwegian Championships, and had a career best throw of 68.12 metres. The cooperation proved fruitful as Thorkildsen soon broke the 80 metre barrier, throwing 83.87 metres at Fana stadion in June. This was a world junior record till 2011. Participating in his second European Junior Championships, he won a silver medal behind Aleksandr Ivanov. Both competed at the World Championships in Edmonton, but while Ivanov managed to reach the final, Thorkildsen finished last in the entire competition with only 68.41 metres. When asked to comment on his own throwing he described it as "completely awful".