Robson began his professional career with Rangers, but failed to break through to the first team at Ibrox. In October 1997, he signed for Inverness Caledonian Thistle, and although not always a first team regular in his early Inverness career, helped them win promotion from the Second Division in 1999. Robson spent most of the 1999–2000 season on loan at Forfar Athletic, but thereafter returned to establish himself in the Inverness line-up.
Dundee United
Dundee United submitted a bid for Robson in May 2003 Despite being sent off on his United début, he became a regular in the United team. Robson missed only two matches throughout the 2004–05 season, finishing as United's second top scorer with nine goals, and signed a new three-year contract at the end of the season. Robson scored the goal that ensured United's survival in the SPL in the final game of the season against his old club Inverness CT.