Background Premedication of cancer therapy against nausea and vomiting (NV) and hypersensitivity reaction (HS) is essential for good patient management. However, this prescription is not always optimal. Today, as a large part of cancer therapies are administered in day hospitals (DH), premedication taken on the day of the cancer treatment is injected as a 30-min infusion. Objective To assess compliance with recommendations for premedication prescription and intake; to analyse patient attitude about switching to exclusively oral forms taken at home. Method The study is conducted in the medical oncology DH of a French Hospital from 17 January to 25 February 2022. The data collection is carried out as an individual interview, associated with the distribution of two questionnaires. Data are coupled with the premedication set up on our software and the last medical report. Intakes are considered optimal when recommendations, tolerance, background, and adherence of the patient are taken into account. Results Seventy patients were included for interviews. Regarding software prescriptions, our configuration was consistent with recommendations in 100% of cases for HS and 37% for NV. Intakes were compliant in 51.4% of cases, non-compliant in 17.1% and debatable in 31.5%. Disparities between the practices of different physicians were identified. Regarding the feasibility of oral substitution, it could concern 63.5% of patients. Conclusion This work makes it possible to improve the management of all patients and to make the operation of the care unit more fluid.