The present invention is concerned with monitoring systems (1) for medical liquid dispensing devices. The systems are intended for use in any medical setting wherein a medical liquid container (4), such as an infusion bag with fluid, is to be infused into a patient and are aimed at reducing the need for visual checking by nurses or other medical assistants. This is achieved by a combination of an identification unit (2), which identifies a medical liquid container and optionally the patient to be treated, a weight monitoring unit, which measures the weight of the medical liquid container when liquid is dispensed therefrom, and a processing unit (3), which processes and/or stores data that are acquired from the identification unit and the weight monitoring unit.