BACKGROUND: Medication reconciliation is relevant in transitional care, however, given limited resources, it is necessary to identify the patients who benefit most from this activity. AIM: To validate criteria to identify patients at high risk of medication errors undergoing major orthopedic surgery. METHOD: Delphi Method in 3 phases, April to June 2023, to obtain consensus on the inclusion criteria, previously defined. Each expert rated criteria according to a 5-point Likert scale. Consensus was assumed in round 1 if the rate average was more than 4 (inclusion) or less than 2 (exclusion) and in round 2 and 3 if 50% of the responses were more than 4 (inclusion) or less than 2 (exclusion). It was possible to suggest the inclusion of new criteria. RESULTS: 10 experts from Faculties of Pharmacy and Medicine participated. In the first phase, consensus was reached on 18 criteria: polypharmacy, anticoagulants, oral chemotherapy (not hormone), immunosuppressants, antiretrovirals, antimyasthenics, insulin, corticoids, neuroleptics, antiarrhythmics, digoxin, carbamazepine, phenytoin, valproate, thyroid drugs, anti-glaucoma, anti-aggregants, and urgent surgery. Systemic antifungals and opioids were suggested. In the second phase, consensus was reached on eleven criteria: anti-parkinsonics, beta-blockers, age more than65 years, length of stay more than 5 days, lamotrigine, diuretics, antidepressants, angiotensin converting enzyme inhibitors, angiotensin II receptor antagonists, anxiolytics, opioids, and systemic antifungals. In the last phase, one criterion reached consensus (sulfonylureas) and one criterion did not reach consensus (calcium channel blockers). CONCLUSIONS: We develop and validate a list of 30 criteria to identify patients at high risk of experiencing medication errors undergoing major orthopedic surgery. These may help improve human resource management for clinical pharmacy activities by prioritizing patients who would benefit most.