QuitWorks is a Massachusetts referral program that links health care organizations, providers, and patients to the state's tobacco cessation quitline and provides feedback reporting. Designed collaboratively with all major Massachusetts health plans, QuitWorks was launched in April 2002. In 2010, approximately 340 institutions and practices used QuitWorks. Between April 2002 and March 2011, approximately 3,000 unique providers referred patients and 32,967 tobacco users received referrals. An analysis of QuitWorks data showed 3 phases in referrals between April 2002 and March 2011: referrals increased from April 2002 through November 2005, plateaued during December 2005 through January 2009, then substantially increased during February 2009 through March 2011. Factors responsible include partnerships with stakeholders, periodic program promotions, hospital activities in response to Joint Commission tobacco use measures, service evolutions, provision of nicotine replacement therapy for referred patients, and electronic referral options. QuitWorks' history demonstrates that tobacco cessation referral programs can be successfully sustained over time; reach substantial numbers of tobacco users, benefit providers and health care organizations; and contribute to sustainable systems-level changes in health care.