The primary mission of The Acadia Hospital is the provision of both hospital-based and community-based mental health and substance abuse treatment services to the people of Maine. Reflecting the caring nature of its mission, The Acadia Hospital is committed to providing quality services which foster dignity and a positive environment for children, adolescents, and adults with mental health and chemical dependency problems and to advocating for their mental, physical and spiritual well-being.

The services of The Acadia Hospital are responsive to individual needs and must be high quality, cost-effective, and accessible, achieving a balance between community needs and available resources. The Acadia Hospital shall seek to continually improve services by promoting education of patients, staff, students, families, and the general public in matters of mental health and substance abuse. The Acadia Hospital encourages non-patient financed clinical and non-clinical research within guidelines approved by the Board of Directors.

As part of the regional network of Eastern Maine Healthcare, the mission of The Acadia Hospital shall be at all times consistent with and supportive of the goals of Eastern Maine Healthcare.