The effects of perioperative dialogue have been studied using qualitative methods, describing patient satisfaction with their care. However, they have not been studied in patients with peritoneal carcinomatosis who undergo major surgery, nor with quantitative variables. The aim was to study the use of pain medication and length of hospital stay following cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in patients who received, versus those who did not receive, perioperative dialogue. The study had a quantitative, retrospective and comparative design including 89 audits. Of these, 37 patients received perioperative dialogues, and 52 patients did not (the control group). The result showed that by postoperative day six, patients who received a perioperative dialogue experienced pain less frequently than patients in the control group. However, no differences between the groups were noted with regard to pain medication consumption and length of hospital stay. To ease their worries, all patients in both groups used benzodiazepines. The perioperative dialogue may be studied quantitatively, but it must involve the patient, who is an equal partner in the dialogue. Structured validated self-reporting measures may be used systematically before and after surgery in order to evaluate the perioperative dialogue using quantitative measures.