Purpose: The purpose of this study was to identify the factors associated with the discontinuation of patient controlled analgesia (PCA) after surgery. Methods: The data of 1,092 adult patients that were over 20 years of age and underwent PCA after surgery in the Gachon University Hospital from May 1 to June 30, 2017, were collected through the patients’ Electronic Medical Record (EMR). The collected data was analyzed via the use of the Chi-test, t-test and multivariate logistic regression analysis using SPSS 18.0 program. Results: The postoperative PCA discontinuation rate was 26.1%. It was associated with various symptoms, such as those of nausea, dizziness, and headache. The PCA discontinuation was also related with female (odds ratio, OR=1.75; confidence interval, CI=1.09-2.82), nausea (OR=105.27; CI=61.03-181.58), total intravenous anesthesia (TIVA) of the thyroidectomy (OR=10.43; CI=5.01-21.70). Conclusion: It is necessary to provide additional medication and nursing interventions to reduce nausea, which is the symptom associated with PCA discontinuation, especially in the operation of female subjects and thyroidectomy under TIVA. That is, those who are at a high risk for PCA discontinuation should be able to administer additional antiemetics or reduce non medication nursing interventions.