In a match against Port Vale on the 29 April 1999, Robinson made a poor tackle on Vale player, Stewart Talbot, breaking Talbot's leg. The injury kept Talbot out of the game for 10 months and resulted in legal action from the player. Robinson had become known for his ill-discipline and overly aggressive playing style. Out of 252 Watford appearances he was booked 63 times and sent off three times. One of these sendings off came in the 1998–99 play-off semi-final against Birmingham City, which saw him miss the second leg. He did feature, however, in the club's 2–0 play-off victory against Bolton Wanderers.
Robinson made 32 appearances for Watford in their Premiership season, and stayed with the club when they returned to Division One. In 2001–02, under new manager Gianluca Vialli, Robinson adopted a more disciplined attitude, which continued under the reign of Ray Lewington.
Robinson was touted as a potential England left back by Bryan Robson and others. His first goal for West Brom was an injury-time headed equaliser at Villa Park in April 2005, which earned him the club's Goal of the Season award. The draw was one of several key results that enabled Albion's "Great Escape" from relegation.
In June 2006 Watford attempted to re-sign the player from West Brom for £1.4m. However this was rejected by manager Bryan Robson and chairman Jeremy Peace, with Robinson considered vital if the team is to realise its ambition of a quick return to the Premier League. Robinson ultimately committed his future to Albion by signing a new three-year contract in July 2006.
On October 28, 2006, Robinson fractured Birmingham City captain Damien Johnson's jaw in two places in a collision during a local derby. The incident drew criticism from Birmingham manager Steve Bruce, who believed Robinson's use of the elbow to be a deliberate act. Robinson was shown a straight red card by referee Nigel Miller.
Robinson was the subject of a £1.5 Million bid from Premiership team Wigan Athletic in August 2007 as a replacement for Leighton Baines, who had been sold to Everton. The move fell through however, when he failed a medical at the JJB Stadium. In early November he was named in the Championship Team of the Week following Albion's 3–0 win at his former club Watford. He made the Team of the Week once again following Albion's 4–3 home win against Colchester United on 29 March 2008. Robinson was named in the PFA Championship Team of the Year, alongside team mates Jonathan Greening and Kevin Phillips, after helping Albion win promotion to the Premiership as league champions.