Two types of circuits of injectable cytotoxic drugs still exist in our hospital: one with pharmaceutical centralization of the preparation and the other without. Our goal is to evaluate each circuit from two points of view: quality of patient care and protection of persons handling cytotoxics. For this evaluation, an original assessment was performed before and after centralization in the same pilot health care unit (two periods of 6 weeks each). To evaluate the prescription-preparation-administration process, six checklists consisting as a whole of 158 observable criteria have been constructed. These criteria have been weighted according to the risk of compromising the quality of patient care and the safety of persons. A total of 117 processes have been observed before centralization; after centralization, 91 were observed. From a qualitative viewpoint, we show that the cost of drugs stocked in the medicine chest of the health care unit has been reduced by 80%, that the flow of information between the different participants in the circuit varied, and that two types of dysfunctions exist: organizational and relational. From a quantitative viewpoint, we demonstrated that pharmaceutical intervention improves the quality of patient care (x2 test, P < 0.001) and reinforces the protection of manipulators (x2 test, P < 0.001). Pharmaceutical centralization of the preparation of cytotoxic drugs increases the efficiency of the circuit, from the prescription to administration.