The new Medical Council begins its work today allowing for a public complaints procedure against medics.
The reformed regime includes rules on fitness to practise and possible sanctions with a majority of lay members sitting on a ruling committee.
And in order to maintain openness, cases will be held in public unless the Fitness to Practise Committee decides otherwise.
Minister for Health Mary Harney said it was the next step in implementing a modern, reformed system of regulation for the medical profession.
"I wish the new Medical Council well in taking up their important and essential role and I would like to reiterate my commitment to support their work," she said.
Other reforms including registration, medical education and training and maintenance of professional competence will come into force over the coming months.
One of the Council's first duties will be to elect a president and vice-president. It will be in office for the next five years.