Monk won the Winmau World Masters in 1996, where he beat Richie Burnett 3–2 in the final.
Monk's best run in the BDO World Darts Championship came in 1998 and 2002 when he reached the semi-finals, losing to Raymond van Barneveld and Mervyn King respectively.
Monk was also part of what is often cited as one of the all-time great matches at Lakeside in 2003 when he defeated Tony O'Shea 3–2 in the Last 16 in a sudden death leg, with Monk's end average being 97.08 to O'Shea's 94.05.
Monk reached the quarter-finals of the 2003 UK Open, a run which included a 9–8 victory over the 2003 PDC World Champion John Part in the Last 16, but Monk was still a BDO/WDF member at the time.
In the 2010 PDC World Championship, he was drawn against Phil Taylor in the first round and lost three sets to nil.