Descriptive data about the use of medical information software were gathered from physicians who were early users of these resources. Eight clinically active internists and medical subspecialists were lent a microcomputer loaded with six commercially available medical information software products. Participants used the software for two weeks to answer questions arising in their practice and completed written questionnaires. They recorded a total of 50 questions (between 3 and 11 per participant per two-week study period). Using the workstation, participants answered 20 questions (40% of the total), partially answered 16 questions (32%), and did not obtain useful information for 14 questions (28%). Participants found answers outside the workstation to 8 of the 14 questions (57%) not answered by using the software. The most common question topic was drug information (16 questions, or 32% of the total). The most common problems encountered using the workstation were retrieval of incomplete information (20 questions, or 40% of the total) and difficulty navigating the software (16 questions, or 32%). Other problems included difficulty translating clinical problems into questions, inappropriate resource selection, inadequate training for using the software, and excessive time required to access information. The study highlights several opportunities for medical librarians and others involved in clinical information management to facilitate the use of computer software for solving clinical problems.