Aims and Objectives: This study aimed to analyse the association of preoperative pain beliefs with postoperative pain levels in abdominal surgery patients. Background: Postoperative pain is related to not only clinical and demographic characteristics but also pain beliefs. The perception, intensity and expression of pain as a subjective experience varies among individuals and cultures. Personal beliefs about pain play an important role in pain experiences and responses. Design: This cross-sectional study consisted of 126 abdominal surgery patients admitted to the General Surgery and Gynecological Surgery Clinics between September 2018-January 2019. The STROBE (Strengthening The Reporting of Observational Studies in Epidemiology) checklist was used as a guideline for this study. Methods: Data were collected through descriptive information forms, pain characteristics questionnaires, Visual Analogue Scales and pain beliefs questionnaires. Oneway variance analysis and Pearson's correlation and t tests were used for data analysis. Results:The mean age of the participants was 48.63 ± 14.27 years. A total of 37.3% of the participants experienced moderate pain and 35.7% experienced severe pain at the 8th postoperative hour. Pain intensity significantly decreased at 16, 24 and 32 h postoperatively. In the predischarge interviews, 92.1% of the patients expressed limitations in physical activities due to pain. There was a relationship between 8-16 h postoperatively and sex and pain expectancy. Mean scores obtained from the organic and psychological beliefs subscales of the Pain Belief Questionnaire were 3.12 ± 0.79, and 2.37 ± 1.11, respectively. The psychological beliefs score was negatively associated with the level of education, and the organic beliefs score was higher for those participants who had undergone gynaecological surgery. There was a weak and positive correlation between the organic beliefs and psychological beliefs subscales of the Pain Beliefs Questionnaire. Conclusion: Patients had moderate to severe postoperative pain, and sex and pain expectations affected the experienced level of pain. Most participants believed that the pain was organic in origin. The level of education exerted a significant impact on pain beliefs. Relevance to clinical practice: Characteristics and perception of pain and pain beliefs are important factors that should be determined to personalise pain relief care and maintain effective pain management.