PURPOSE To evaluate patients in a smoking cessation support group using the Nursing Outcomes Classification (NOC). METHODS Prospective observational cohort study conducted with 21 patients participating in a smoking cessation support group. Data were collected using an instrument consisting of 2 NOC outcomes and 20 indicators, applied during each of the six support group meetings. FINDINGS The two NOC outcomes, Smoking Cessation Behavior (1625) and Substance Withdrawal Severity (2108), showed statistically significant differences over time in many of their indicators. CONCLUSIONS The NOC outcomes demonstrated the clinical evolution and behavioral improvement of patients during the smoking cessation process. IMPLICATIONS FOR NURSING PRACTICE The findings highlight important elements of the evaluation of behavioral change and severity of withdrawal symptoms.