OBJECTIVE This study was conducted to determine the prevalence and severity of postoperative pain in the first 24 hours after surgery and to emphasize the importance of postoperative pain assessment. METHODS A descriptive study. METHODS This study was carried out on May 21, 2019 with 898 patients who had completed the postoperative 24th hour in the surgical clinics of 10 training and research hospitals in Istanbul, the capital of Turkey. Point prevalence was used in the study. Data were collected using a questionnaire developed by the researchers and the Revised American Pain Society Patient Outcome Questionnaire. Descriptive statistics were presented as frequency, percentage, mean, and standard deviation. Nonparametric tests were used for data without normal distribution (Kolmogorov-Smirnov Test, P < .05). Two-group comparisons were performed using the Mann-Whitney U test. The Kruskal Wallis-H test was used for the comparison of three or more groups. Statistical significance was set as P < .05. RESULTS The three main types of surgery were general surgery with 31.8%, gynecologic surgery with 12.9%, and orthopedic surgery with 12.7%. The mean lowest level of pain felt by the patients included in the study in the first 24 hours was 3.90 ± 2.94, and the mean highest level of pain was 6.38 ± 4.45. CONCLUSIONS Postoperative pain is a subjective phenomenon and may be affected by factors such as type of surgery, previous experience of surgery, duration of surgery, the length of the surgical incision, the type of anesthesia, the quality of postoperative care, individual characteristics and experiences, and fear anxiety; thus, the experience of pain may vary from person to person.