Physician's Desk Reference and Database is a Finnish collection of computerized primary care guidelines. The program has been in clinical use since 1989. For this study, a function producing a log file of all searches was added to the program. Two hundred twenty-seven users returned log files that contained 15,267 searches. The users made 3.12 (range 1-10.4) searches per day. The average time needed to find and read an article was 4.9 minutes. Sufficient facts were found in 71% of the searches. Dermatology was the most popular field of interest, followed by infectious diseases and cardiology.