Chemotherapeutic agents are high-risk drugs with a high potential for error and serious harm. International studies show that 5-15% of all chemotherapy patients are affected by medication errors. 60% of these errors had the potential to cause harm to patients, 13% resulted in harm and 1% of patients were seriously harmed1. The most common medication errors in the administration of chemotherapy drugs are administration errors and can therefore be observed by the patients themselves. Chemotherapy patients in particular, who often experience the same treatment steps due to their longer treatment duration, often recognise deviations from the usual routine and notice when something is different than usual. They have time to look at the identifying features of chemotherapy and recognise mistakes. In the best case scenario, they communicate these observations, changes or uncertainties to the healthcare professional in charge. In this way, the active involvement of patients provides an additional safety barrier that can be used to support the medical staff. With this in mind, the Quality Management and Clinical Risk Management department has initiated a project together with the Department of Internal Medicine (tumour research), the oncological care experts at Essen University Hospital, the patient networking and self-help officer and other important interfaces such as the LVR Clinic to make the administration of chemotherapeutic agents even safer and to actively involve patients in their treatment.