As an 18-year-old in 2006, he became the youngest to play for Sweden at the World Championship, playing on the top line with Henrik Zetterberg and Johan Franzen. He won gold, playing the last four games of the tournament, filling a spot previously held for Daniel Alfredsson.
Playing in his home country at the 2007 World Junior Championships, Backstrom led his team and finished second behind Patrick Kane with seven assists for the tournament.
He played alongside fellow 2010 Olympian Patric Hornqvist at the 2008 World Championships and together they combined for 13 points (9-4-13). Sweden lost to Finland in the bronze medal game.