On 9 October 2004, Hajnal played his first match for Hungary in Solna against Sweden and on 17 October 2007, he scored his first international goal in a friendly match against Poland. The final result was 1–0 to Hungary. Hungary finished a disappointing sixth in their qualifying group for UEFA Euro 2008 and have been out of the running for a place in Austria and Switzerland next year since the beginning of the qualification period. The competition from Greece, Norway and Turkey was simply too strong for Hajnal and his team mates, who nevertheless beat Bosnia-Herzegovina home and away during the campaign.