Aims: This study aimed to investigate patients' attitudes towards day-case hip and knee arthroplasty and to describe patient characteristics associated with different attitudes, with the purpose of providing an insight into the information requirements for patients that surgeons should address when informing patients about day-case surgery. Methods: A total of 5,322 patients scheduled for hip or knee arthroplasty between 2016 and 2022 were included in the study. Preoperatively, patients were asked if they were interested in day-case surgery ('Yes', 'Do not know', 'No'). Patient demographics including age, BMI, sex, and patient-reported outcome measures (PROMs) such as the EuroQol five-dimension three-level questionnaire (EQ-5D-3L) were examined within each attitude group. Additionally, changes in attitude were assessed among patients who had completed the questionnaire in association with prior hip or knee arthroplasty. Results: Of the surveyed patients, 41.8% were interested in day-case surgery (n = 2,222), 20.8% responded 'Do not know' (n = 1,105), and 37.5% were not interested (n = 1,995). Patients who were not interested had a higher mean age ('No', 70.2 years (SD 10.0) vs 'Yes', 65.2 years (SD 10.7)), with a majority being female ('No', 71.9% female (n = 1,434) vs 'Yes', 48.6% female (n = 1,081)). Approximately 20% of patients responded 'Do not know' regardless of age, sex, and PROMs. Patients reporting anxiety/depression based on EQ-5D-3L more frequently answered 'No' (56.9%; 66/116) compared to those not experiencing anxiety/depression (34.9%; 1,356/3,890). Among patients who responded 'Do not know' before their first surgery, over 70% changed their attitude to either 'Yes' (29.9%; 38/127) or 'No' (40.9%; 52/127) at their subsequent surgery. Conclusion: From 2016 to 2022, 58.3% of hip and knee arthroplasty patients expressed uncertainty or no interest in day-case surgery. In connection with current initiatives to increase the number of day-case arthroplasty procedures, there should be a focus on informing patients to address the prevalent negative or uncertain attitude. Further research is needed to investigate what preoperative information patients consider crucial in their decision-making process regarding day-case surgery.