In hospitalized patients, it is essential to question and record the patient’s history of allergy to a known drug in order to prevent a possible medication error. Patients may have extra allergy labels due to vague symptoms that do not correspond to true allergic reactions or lack of information. Occasionally, allergic reactions may occur when patients with allergies are not labeled. An inaccurately defined history of allergy leads to increased use of broad-spectrum antibiotics, increased potential side effects, higher risk of infection by resistant bacteria, increased treatment costs, and prolonged hospitalization. The present study aims to determine the frequency of drug and food allergies in all patients hospitalized in the general surgery service over a one-year period and to investigate the effects of our approach in clinical practice on the treatment process in case of a history of allergy.