BACKGROUND: Quitline smoking cessation counseling results in a mere 12% success rate. Testing of new telephone-delivered cessation counseling approaches is needed. OBJECTIVE: Determine the feasibility of the first telephone-delivered Acceptance and Commitment Therapy (ACT) intervention for smoking cessation. DESIGN: Fourteen adults (57% racial/ethnic minority, 8/14) in a single-arm study. Counselor proactively delivered a 5-session (90-min total) ACT telephone intervention for smoking cessation. Hypothesized ACT processes were self-reported at baseline and posttreatment. Smoking status was self-reported at baseline, 20-day posttreatment (93% retention, 13/14), and 12-month posttreatment (93% retention, 13/14). RESULTS: (a) Delivery length and duration: average of 3.5 calls and 81.9-min intervention duration. (b) Receptivity: 100% (14/14) felt respected by the counselor, 86% (12/14) said that intervention was a good fit, and 93% (13/14) said that intervention helped them quit. (c) ACT processes: (i) acceptance of physical cravings, emotions, and thoughts that cue smoking increased from baseline to posttreatment (p = .001, p = .038, and p = .085, respectively) and (ii) commitment to quitting increased from baseline to posttreatment (p = .01). (4) Intent-to-treat cessation outcomes: (i) at 20-day posttreatment, 43% (6/14) had not smoked the day of the survey and 29% (4/14) had not smoked in past 7 days and (ii) at 12-month posttreatment, 29% (4/14) had not smoked at all in past 12 months. These quit rates are over double the 12% quit rates of current standard telephone counseling. CONCLUSION: Telephone-delivered ACT shows promise for smoking cessation and warrants future testing in a well-powered randomized trial.