Sixty-four men and women with criminal records for drink-driving have been approved for a career in teaching by the General Teaching Council for Wales (GTCW) over the past two years, it has emerged.
According to figures obtained by TES Cymru, just two drink drivers seeking teacher registration were turned down by the regulatory body.
The council has launched 192 investigations following positive Criminal Records Bureau checks since mid-2006. Nineteen went on to a public hearing.
Hayden Llewellyn, deputy chief executive of the GTCW, said drink-driving was the offence most commonly raised during CRB checks. "That's the same with other official regulators as well," he said.
He said most were newly qualified teachers with recent drink-drive convictions or older people with past convictions who were looking to change careers.
According to Mr Llewellyn, a GTCW committee considering the applicant takes into account the number and seriousness of the offences, coupled with their experience, qualifications and their overall fitness to practise.
Last month, a woman from Swansea was allowed to register as a teacher despite serving a driving ban for being three times over the drink-drive limit. The committee was impressed by her "attitude and commitment", backed by a series of glowing references.
Last month's public hearing in Cardiff heard that a newly qualified teacher in her twenties had drunk six glasses of wine and started to drive home after a row with her boyfriend in May 2007.
It was argued that drink-driving is a "reckless and dangerous offence" that could harm the reputation of the teaching profession.
But the woman's union representative, David Browne, of the NASUWT, said: "Teachers are humans, they all make mistakes. She will have the stigma with her for the rest of her life."
When Gareth Jones, secretary of heads' union ASCL Cymru, asked the aspiring modern foreign languages teacher how she would react if her pupils raised the subject of drink-driving, she said she would be honest.
Speaking after the case, Mr Jones said individual governing bodies would decide whether a teacher with a conviction is suitable for their school, but a drink-drive record is unlikely to put them off.
Iwan Guy of the National Association of Head Teachers Cymru, said heads are open-minded about drink-drive convictions, and suggested the majority would accept the GTCW's verdicts in the drink-drive cases.
Carole Whittingham, who set up the Campaign Against Drinking and Driving (CADD) in memory of her son who was killed by a drink driver, said each case should be taken on its own merits.
"I certainly wouldn't want to see habitual offenders allowed to teach in the classroom," she said.