He first started playing for the New Wave of British Heavy Metal band White Spirit. He then joined the band Gillan which was formed by Deep Purple singer Ian Gillan. When Gillan broke up, Gers joined Gogmagog in 1985. During the recording of the song "Bring Your Daughter... to the Slaughter", he was asked to join Iron Maiden in place of Adrian Smith. Since then, he has remained with the band even when Smith rejoined the band in 1999.