Background: Patients expect nurses to be both technically competent and psychosocially skilled. Enhancing the quality of patient care and patient safety in healthcare settings has increased, resulting in limited opportunities for students to practice clinical skills in healthcare settings. Achieving competence in these skills is viewed as an essential task to be completed during the school curriculum. Objective: The purpose of this study was to evaluate the use of self-observation through cellular recordings as an adjunct to the clinical skills teaching of a blood sugar test to undergraduate nursing. Design: The research design consisted of pre- and post-test consecutive experimental design through a control group. Settings: This study targeted nursing students enrolled in baccalaureate programs running in Korea. Participant: The participants were 64 students including 34 for the experimental group and 30 for the control group. Methods: Those in the control group received standard teaching methods using lectures and skills classes and facilitated the use of self-study methods. Those in the experimental group received standard teaching using lectures and skills classes and facilitated use of cell phone recorded self-observation. The self-confidence of practicing a blood sugar test, satisfaction with the learning method, self-study participation, level of interest in nursing practice, and self-directed learning ability were measured using questionnaires. Results: Significant between-groups differences were detected in self-confidence of practicing a blood sugar test (t = 2.067, p = 0.043), satisfaction with the learning method (t = 2.818, p = 0.044), self-study participation (χ2 = 7.635, p = 0.022), and average self-directed learning ability (t = 3.202, p = 0.002). Conclusions: Self-observation through cellular phone recordings is an effective learning method as an adjunct to teach clinical skills.