Ljungberg was signed by Arsenal in 1998 for £3 million. Arsenal scouts watched him for over a year and Arsenal's manager, Arsène Wenger, took the unusual step of authorising the signing after watching Ljungberg play for Sweden in their victory against England on television, without seeing him play live. Seeing Ljungberg's performance against England only confirmed to Wenger that Ljungberg could cope against English opponents, and he was signed shortly after. Ljungberg proved himself without difficulty and scored on his debut on 20 September after coming on as a substitute against rival club Manchester United, the match ending 3–0. Ljungberg made 21 appearances across all competitions in his first season, and 43 in his second (1999-2000). He missed the 2000 UEFA Cup Final due to a rib injury. At the end of his third season at Arsenal, 2000–01, they got to the 2001 FA Cup Final. Ljungberg scored to put Arsenal 1-0 up but then Liverpool scored two late goals to win 2-1. This made Ljungberg the first player to score a goal at an FA Cup final outside England, with the game being the first final at the Millennium Stadium in Cardiff.