Clinicians in patient care settings must be able to locate relevant recent medical literature quickly. Computer literacy is increasing, but many clinicians remain ill at ease with search strategies for online bibliographic databases. As part of an ongoing project to simplify the translation of clinical questions into effective searches, a Unified Medical Language System (UMLS) Metathesaurus tool was designed. The authors compared bibliographic searches by relatively inexperienced users employing only GRATEFUL MED to searches done using GRATEFUL MED augmented with this tool. The users were clinicians examining questions related to a test set of clinical cases. Their problems and successes were monitored; the results suggest that the addition of a thesaurus helps resolve some problems in citation retrieval that trouble the novice user. By helping the user understand indexing terms in context and by reducing typing errors, a thesaurus can help provide an intelligent solution to lexical mismatches in bibliographic retrieval.