There is scarce information on antibiotics prescription habits among dentists in general. The present investigation was undertaken to study some patterns of antibiotics prescription among Norwegian dentists. A total of 459 dentists (approximately 10% of Norwegian dentists) were randomly selected, and to each was mailed a letter describing the survey, accompanied by a questionnaire about age, type of practice, educational background and pattern of prescription of antibiotics. 78% of the dentists responded to these questions. The results indicate that during a typical week, 32% did not prescribe antibiotics, whereas 5% wrote greater than 5 prescriptions. The mean weekly number of prescriptions per dentist was 2.04. Periodontists and oral surgeons prescribed antibiotics significantly more often than did general practitioners and other disciplines. In addition, those with research and/or teaching experience seemed to prescribe significantly more often than those without. More than 1/3 of the sample indicated that they may prescribe antibiotics when treating periodontal diseases. Compared with other disciplines, periodontists prescribed such drugs significantly more often when treating periodontitis, but significantly less often in acute gingivitis, stomatitis and herpes simplex infections. Moreover, 22% of the dentists might prescribe antibiotics when the patient is in pain, 73 and 38% in cases of abscesses with or without generalized malaise, 2.5% in endodontic therapy, 60% to prevent general complications, and 68% for prophylactic use if the patient revealed a history of endocarditis. Norwegian dentists are somewhat restrictive in their prescription of antibiotics, but they mostly prescribe the correct drugs for the different conditions.