Community members and health representatives celebrated the milestone by acknowledging all the hard work invested in the unit's creation.

The first sod on the project site was turned in December 2017 and the new unit first started accepting patients in February 2019 while stages two and three of the project were completed.

Mid North Coastal Local Health District governing board chair Warren Grimshaw AM said the opening was an exciting day for mental health services in the region.

"Today is the official opening of our new mental health unit which is the culmination of extensive planning and work," Mr Grimshaw said.

"We have worked incredibly hard to understand the needs of the community and the mental health unit has been a high priority for the Mid North Coast Local Health District.

"The facility itself has a large, relaxed feel and lots of natural light for carers and our patients."

Mr Grimshaw said the opening officially marked the new era of mental health care in the region.

"Thought the design and build process we have consulted extensively with consumers and the community to ensure the best facility possible," he said.

Sara Shaughnessy, director of mental health and integrated care for the Local Health District, said the opening of the new unit represented a collaboration between mental health consumers and the Local Health District.

"The community have been utterly generous in their engagement with us to ensure the unit is best equipped to help people," Ms Shaughnessy said.

"It is important to acknowledge lived experience with mental health and we have consulted consumer groups and the community at every stage of this project.

"This unit is the outcome of the Local Health District putting mental health as a priority in the Port Macquarie Hastings and Macleay region so we can provide the best care possible."

The $17.5 million project provides secure patient rooms with natural light, quiet spaces for relaxation, a multi functional activity room, dedicated family and carer rooms, dining and lounge facilities and secure landscaped courtyards.

Port Macquarie MP Leslie Williams said the completed project will provide a significant improvement to the delivery of mental health services in our area.

"I congratulate everyone involved in the delivery of this new unit," Mrs Williams said.

"We very much welcomed the input from consumers, carers and members of the Aboriginal community who were all key components in the planning and schematic design phase, ensuring the facility is equipped to meet the needs of the community now and into the future."