On September 8, 1999, Nakazawa debuted for the Japan national team against Iran. In 2000, he was selected the Japan U-23 national team for 2000 Summer Olympics and played all 4 matches. He also played at 2000 Asian Cup and won the champions. However his opportunity to play decreased after the 2000 Asian Cup. From autumn 2003, he became a regular player as center back with Tsuneyasu Miyamoto. In 2004, he participated in the 2004 Asian Cup. He played all 6 matches and scored 3 goals, and Japan won the champions again. He also played at 2006 World Cup. In 2007, he played in the 2007 Asian Cup, but this time the team failed to defend the title and finished the 4th place. In 2010, he was selected Japan for 2010 World Cup. He played all 4 matches as center back with Marcus Tulio Tanaka. Nakazawa played 110 games and scored 17 goals for Japan until 2010.