Since the introduction of new German health legislation, operations formerly performed on an in-patient basis have been transferred to the out-patient sector. Due to this development evaluating the postnarcotic arousal period has become increasingly important. Vigilance, reactivity and state of health determine a patient's well-being and time of discharge after an operation and consequently influence economical and legal issues. Former studies investigating the arousal period have mainly focused on patient interviews and assessment of patients by staff. The aim of our study was to objectivize postnarcotic vigilance and reactivity (critical flicker fusion frequency and multiple choice reaction) using neurophysiological monitoring (psychometric system Combitest 2: CFF, EWR, MWR). The applied methods have been defined as valid, reliable and sensitive tools to investigate this question. Inter-individual and gender-specific differences as well as variations due to the type of anaesthetic employed can be detected. The study participants assessed the test battery's practicability and overall described this method as easy to use. Vigilance (CFF), basic and complex sensomotor reactivity (performance in simple and multiple choice tests) were restored after a postanaesthetic phase of 90 minutes (narcotics applied: isofluran and propofol). The results show that the use of modern anaesthetics does not justify the current medical and legal claim to 6 hours of postanaesthetic observation. The computer-supported psychometric system Combitest 2 has recently been used to assess the arousal phase after application of different types of anaesthetical procedures (TIVA, volatile, balanced) and has been found to be superior to parameters traditionally used to assess discharge criteria (time until patient opens eyes, orientation concerning time and location, time spent in postanaesthetic recovery room). Besides employing our study methods, subjective factors such as well-being and pain sensation should also be evaluated when determining the time of a patient's discharge.