Objective: To explore the practical effect of applying the 3N quality control circle tool in improving outpatient nursing satisfaction, and to provide a reference for clinical nursing quality improvement. Methods: A 3N quality control circle was established in the Outpatient Department of Qingpu Hospital Affiliated to Fudan University in March 2025. The period from March 18th to 31st, 2025 was set as the pre-implementation stage, and period from June 30th to July 13th, 2025 as post-implementation. A total of 50 patients were included in each stage, serving as the control group and the observation, respectively. The changes in outpatient nursing satisfaction, the proportion of patients who considered there were deficiencies in the core items, and other related indicator before and after the implementation were compared. Results: Compared with before the implementation, the satisfaction rate of outpatient care increased from 80.0% (40/50) to 98.0% (49/50) after the implementation of 3N quality control circle. The proportion of patients who considered that there were deficiencies in the core items (polite nurse service; affability nurse’s language; nurse’s ability to answer questions; practical and effective health education content in the outpatient clinic; nurse’s operational proficiency, ability to care for patients’ feelings, and protect patients’ privacy) were significantly reduced (pre-implementation: 40.0% (20/50), 32.0% (16/50), 30.0% (15/50), 16.0% (8/50), 12.0% (6/50); post-implementation: 10.0% (5/50), 6.0% (3/50), 4.0% (2/50), 0 (0/50), 0 (0/50)). The differences were statistically significant (χ2 values were 12.000, 10.981, 11.977, 8.696, 6.667, P values were 0.001, 0.001, 0.001, 0.003, 0.010). In terms of intangible achievements (team spirit, sense of responsibility and honor, activity confidence, professional knowledge, communication and coordination, application of quality control methods), the circle members showed significant improvement (pre-implementation scores: 3.30±0.42, 3.12±0.51, 2.74±0.61, 3.24±0.51, 3.22±0.61, 2.41±0.52; post-implementation scores: 4.54±0.51, 4.67±0.21, 4.51±0.20, 4.60±0.22, 4.72±0.20, 4.42±0.31), the differences were statistically significant (t values were 12.450, 18.641, 18.289, 16.242, 15.499, 22.023, all P<0.001). Conclusion: The practical effect of the 3N quality control circle in enhancing the satisfaction of outpatient care is quite satisfactory. In the future, the improvement dimensions of the quality control circle can be expanded, a long-term monitoring mechanism for nursing quality can be established, and the outpatient nursing service process can be continuously optimized. Meanwhile, routine training on the application of regular quality control tools by the nursing team can be strengthened to continuously improve the quality of outpatient care.