Thompson was selected for England's summer tour to North America in 2001, where he did well. He made his test debut for England in the 2002 Six Nations with a win against Scotland. He scored his maiden test try against Italy in the 2003 Six Nations, a tournament which saw England win the Grand Slam. Thompson made a significant contribution to England's southern hemisphere tour in June 2003, playing in both victorious tests against New Zealand and Australia.