We studied the self-reported information needs of 47 physicians during a half day of typical office practice. The physicians raised 269 questions about patient management. Questions related to all medical specialties and were highly specific to the individual patient's problem. Subspecialists most frequently asked questions related to other subspecialties. Only 30% of physicians' information needs were met during the patient visit, usually by another physician or other health professional. Reasons print sources were not used included the age of textbooks in the office, poor organization of journal articles, inadequate indexing of books and drug information sources, lack of knowledge of an appropriate source, and the time required to find the desired information. Better methods are needed to provide answers to questions that arise in office practice.