Objectives : A protocol called "critical pathway" was developed to standardize the management of hospital patients the day after they underwent gamma knife radiosurgery. The quality of improvement in patient outcomes was evaluated. Methods : Critical pathway was developed, according to the regulations of the I hospital, by analyzing the medical records of 22 inpatients who underwent gamma knife surgery within the period from January to April 2011 on the day of the surgery. The study included a group of 22 patients admitted to the hospital the day after they underwent gamma knife radiosurgery, between July and September 2011. The control group included 22 patients who had surgery employing the same method within the period from May to June 2011. To measure the effects on quality improvement, the average length of stay, the execution rate of the hospital discharge notice system, daily hospital revenue, and the satisfaction of the patients and the medical team were assessed. The patient questionnaire employed a four-point Likert scale while the medical-staff questionnaire employed a five-point Likert scale. Result : The average length of stay was significantly shorter in the study group compared to the control group (2.3 days vs. 3.8 days, P<0.05). The execution rate of the hospital discharge notice system was higher in the study group (100% vs. 72%) than in the control group. Daily hospital revenues were higher by 264,178 Korean won in the study group when compared to the control group. The study group showed greater satisfaction of patients compared to the control group based on a four-point Likert scale (P<0.05). The study group showed greater satisfaction in medical team compared to the control group based on a five-point Likert scale (P<0.05). Conclusion : The development and implementation of a critical pathway protocol for hospital admission the day after gamma knife radiosurgery is an effective care process that improves the clinical quality.