During his career Westwood has DJed for many radio stations, including the newly formed radio stations Kiss FM (which he co-owned) and LWR in the 1980s, followed by mainstream station Capital FM (from 1987). In December 1994, following a shake up of Radio 1 by the then chief executive Matthew Bannister, he was given the new national Radio 1 Rap Show.

After appearing in the 1987 BBC Open Space documentary "Bad Meaning Good", which was an early work of his own company Justice Entertainment, he achieved TV exposure in the late 1980s, on the ITV programme Night Network, produced by London Weekend Television.

More recently, he presented a series of his own television programme on UKTV channel UK Play, which has since ceased broadcasting. His Radio 1 show was produced by his independent company Justice Entertainment, which also produced Chris Goldfinger's dancehall show for Radio 1 at the time.

He was named Best UK Radio DJ in the MOBO (Music of Black Origin) Awards in 2000, 2003 and 2005. He is a patron of the internal radio station at Feltham Young Offenders' Institution in west London.

Westwood was injured in a drive-by shooting in Kennington, South London, on 18 July 1999, after he had been playing at the Lambeth Country Show in Brockwell Park. According to police reports, gunmen on a motorbike pulled up alongside his Range Rover and shot him and his assistant