Seeks to identify physicians' perceptions of possibilities and obstacles prior to implementing a computerised drug prescribing support system. Details a descriptive, qualitative study, with semi-structured individual interviews of 21 physicians in the Accident and Emergency Department of South Stockholm General Hospital. Identifies four descriptive categories for possibilities and obstacles. Concludes that gaining access to patient drug history enables physicians to carry out work in a professional way--a need the computerised prescription support system was not developed for and thus cannot fulfil. Alerts and producer-independent drug information are valuable in reducing workload. However, technical prerequisites form the base for a successful implementation. Time must be given to adapt to new ways of working.