He started his career with Shrewsbury Town in 1988, and after being voted onto the PFA Team of the Year, moved on to Manchester City for £500,000 in October 1993.
He joined Leyton Orient for £65,000 in March 1997, where he stayed for four years, interrupted by short spells at Wrexham (on loan) and Port Vale.
Hitting 62 goals in 170 games during a difficult period at the Gay Meadow, he had done enough to be picked up by Brian Horton's Manchester City in October 1993 for a fee of £500,000.
Scoring three goals in five games was enough to convince Tommy Taylor to spend £100,000 to bring him to Brisbane Road permanently in March 1997.
He spent four weeks on loan at Wrexham from 14 January 1999 and found the net in four of his five appearances for Brian Flynn's "Dragons".
He moved to Port Vale in March 1999 for £100,000 as part of new manager Brian Horton's spending spree.
He scored four times in eleven games in 1999–2000, including a hat-trick in a 5–1 win over Chester at the Deva Stadium on 28 December.
On 19 November 2010, Aveley announced that Griffiths had been appointed manager of the club with immediate effect and would bring together his ex-management team from Brentwood, consisting of Scott Canham, Gary Foley, Harry McCullum and Dean Parratt.