We evaluated the consultation behaviour of residents using a protocol processing system in routine clinical practice. A total of 125 consecutive patients, of age 16 years or older with an isolated fracture without concomitant lesions, were treated with computer support between 13 October 1992 and 9 June 1993. All eight surgical residents who worked at the emergency ward of the University Hospital in Nijmegen, The Netherlands participated. The mean consultancy time, method of information retrieval, number of correct protocols found, number of windows retrieved and attitude towards ProtoVIEW as a useful information source were estimated. Main results are: a mean consultancy time of 1.5 min per case, residents browsed through the protocol information more often than using keyword search. The correct protocols were found in 98% of the cases while on average a minimum number of text-browse windows was retrieved. Residents were positive about the way protocols were presented and about the information supplied by ProtoVIEW. From this study we may conclude that ProtoVIEW consultation is hardly time consuming, and easy to use. Since keyword search was hardly used, expanding the number of synonyms may stimulate searching by keyword more often.