His professional career began in 1995, his first win was in 1998 at the Australian PGA Championship and the following year Howell won his first tournament on the European Tour . This was followed by six years without a win, but with good placements and his form went steadily upwards. In 2005 and 2006 he was able to record further tournament victories and reached the top 20 in the world rankings . In the European Tour Order of Merit 2006 Howell achieved his best season ranking so far with 3rd place. The 2007 season was unpleasant for him due to injury and he had to say goodbye to the top 100 in the world rankings, to which he could only return in September 2013 after his victory at the Alfred Dunhill Links Championship .
Howell was a member of the victorious European Ryder Cup team in 2004 and 2006 .