BackgroundPain is one of the factors that decrease quality of life. Undergoing surgery is inevitably associated with the sensation of pain, which can affect a patient’s level of acceptance of an illness. The aim of the study was to evaluate the level of acceptance of illness in patients undergoing surgical treatment with relation to the pain perceived by them during surgical treatment and to determine other factors that affect adaptation to illness among patients subjected to invasive treatment.Material and methodsThe study was conducted on a group of 100 patients with mean age of 51.27 (SD=18.98) hospitalized in surgery departments in the Provincial Specialist Hospital in Wrocław, Poland, in April 2016. The Acceptance of Illness Scale (AIS) and the Visual Analog Scale (VAS) for pain were used.ResultsThe mean score of VAS was 3.86 (SD =2.02). The mean score of AIS was 24.42 (SD =7.35). The level of acceptance of illness was significantly negatively correlated with the intensity of pain (p<0.001; r=−0.498), the number of coexisting diseases (p=0.002; r=−0.31), age (p<0.001; r=−0.391), and the period of time since the operation (p=0.007; r=−0.266). Patients taking analgesics showed a significantly lower acceptance of illness than those who did not (p=0.009). A patient’s place of living, education, and sex had no significant impact on their acceptance of illness.ConclusionA higher level of pain translates into a lower adaptation to illness despite the use of analgesics, which may indicate that inadequate pain control leads to a decrease in the acceptance of illness. Further research on monitoring postoperative pain, as well as the development of postoperative prevention programs, is required.