Introduction: Tobacco quitlines (QLs) provide effective evidence-based tobacco cessation counseling, yet they remain underutilized. Barriers to utilization include the lack of referrals by health care providers who typically have little knowledge about QLs and low self-efficacy for providing tobacco interventions. In order to educate providers about QLs, referral methods and tobacco interventions, a case-based online CME/CE program, Refer2Quit (R2Q), was developed. R2Q includes QL education and intervention and referral skills training tailored to provider type (eg, physician, nurse, dental provider, pharmacist) and work setting (eg, emergency, outpatient, inpatient). A module teaching motivational enhancement strategies was also included. Methods: Four health care organizations in Washington State participated in a study examining the effects of R2Q training on fax referral rates in an interrupted times series. Attitudes and self-efficacy toward delivering tobacco interventions was also assessed. Participants were a mix of provider types, including prescribers (20.1%), RNs (46.7%), and others (33.2%). Results: Health care sites that participated in the study increased the fax referral rates (odds ratio [OR] 2.86, confidence interval [CI] 1.52-6.00) as well as rates of referrals that converted to actual quitline registrations (OR 2.73, CI 1.0-7.4). Providers who completed the training expressed significantly more positive attitudes and improved self-efficacy for delivering tobacco services. At follow-up most providers reported increased delivery of tobacco interventions and QL referrals, although only 17% reported increased rates of fax referral. Discussion: Our study suggests that online education builds skills, improves knowledge, and thus increases the number and quality of fax referrals made to QLs by health care providers. Providers nonetheless reported ongoing barriers to providing tobacco services and referral, including lack of reimbursement and patient unwillingness to accept a referral. (Contains 5 tables and 1 figure.)