Iversen began his career as an 18-year-old at Rosenborg where he won two consecutive Norwegian league championships. He moved to Tottenham Hotspur in December 1996, where he scored 64 goals in seven years, and won the League Cup. After a brief spell at Wolverhampton Wanderers, he moved back to his native Norway where he spent two years at Vålerenga and was a contributing factor to Vålerenga's first league championship in 21 years. In 2006, he moved back to Rosenborg, where he won his second consecutive league title, and after another league victory in 2010, Iversen spent 13 months at Crystal Palace, before he signed for Rosenborg for the third time in February 2012.