The Legislative council finally approved the government's proposal to reform the Medical Council on Wednesday, after an earlier version of the bill failed to win lawmakers' support in 2016.
Four new lay members will now be added to the 28-member body, with three from patients' groups and one from the Consumer Council.
Two of the appointed seats will also be directly elected by members of the Academy of Medicine.
The Health Secretary, Sophia Chan, said she hopes the backlog of over 700 complaints can be cleared within three years.
She said: "We are going to have negative vetting legislation to go to the Legislative Council so that we can lay down all the guidelines and also all the legislation related to election of people from patients' organisations.
Also, we have to work to improve the patient complaint system. The Medical council would have to forge ahead with this work, the government would also provide additional resources to assist with the administration."
The amendments, which aim to make the watchdog more efficient in handling complaints about doctors' professional conduct, got overwhelming support from lawmakers from both side of the divide.