The present invention relates to a monitoring system (1, 2, 3) and a corresponding monitoring method for monitoring a patient and detecting delirium of the patient in an unobtrusive manner without the need of on-body sensors. The proposed monitoring system comprises a monitoring unit (10) for obtaining image data (30) of the patient over time, an image analysis unit (12) for detecting motion events of the patient from the obtained image data (30), an evaluation unit (14) for classifying the detected motion events into delirium-typical motion events and non-delirium-typical motion events, and a delirium determination unit (16) for determining a delirium score (32) from the duration, intensity, type, location and/or occurrence of delirium-typical motion events, said delirium score (32) indicating the likelihood and/or strength of delirium of the patient.
