Broad played his first game for Leicestershire 2nd XI in 2004 just before his 18th birthday and impressed enough to be given a full contract for the following season. Broad continued to impress Director of Cricket James Whitaker and made his first-class debut early in the 2005 season against Durham University Centre of Cricketing Excellence. He returned credible figures of 1/40 from 15 overs. His maiden first-class wicket was that of Nick Lamb. Broad followed this appearance with his first County Championship appearance against Somerset at the familiar location of Oakham.