Objective: To establish whether attendance at an education class prior to total hip or knee replacement surgery as part of an enhanced recovery after surgery pathway could decrease length of hospital stay. Methods: A single-site, retrospective cohort study comparing length of stay in hospital for patients who attended and did not attend an education class prior to hip or knee replacement surgery. Patients were stratified into 3 groups according to the predicted likelihood of an extended inpatient hospital stay using the Risk Assessment Predictor Tool. Results: Mean length of stay reduced by 0.37 days for patients who received hip replacement (n = 590) (95% confidence interval (95% CI) –0.74, –0.01, p = 0.05) and by 0.77 days for patients who underwent knee replacement (n = 643) (95% CI –1.23, –0.31, p = 0.001) following attendance at a preoperative education class. Patients undergoing knee replacement who were considered at high risk of an extended hospital stay stayed, on average, 2.59 days less in hospital after attending the class (mean length of stay: 4.52 (standard deviation (SD) 1.26) vs 7.11 (SD 4.18) days (95% CI –4.62, –0.54, p < 0.02). Conclusion: This study supports the inclusion of a preoperative education session in this context for both hip and knee replacement procedures, and indicates that this may be most beneficial for patients undergoing knee replacement who are at risk of an extended length of stay. Lay Abstract: The aim of this study was to compare length of stay in hospital between patients who attended an education class prior to elective total hip or knee replacement surgery, and those who did not attend. A further aim was to establish which patients would benefit most from a preoperative education class, using the Risk Assessment Predictor Tool. The study showed that patients who attended the class spent 0.38 days less in hospital following hip replacement, and 0.77 days less following knee replacement surgery. Patients undergoing knee replacement who were considered at high risk of an extended hospital stay spent, on average, 2.58 days less in hospital after attending the class. These results support the inclusion of a preoperative education class in this context for both hip and knee replacement procedures, and indicate that this may be most beneficial for patients undergoing knee replacement.