To explore the experiences and opinions of family physicians and patients regarding the delay of antibiotic prescriptions, to be dispensed if symptoms persist or worsen over time, in treating upper respiratory tract infections. Qualitative study using semistructured interviews conducted in family practice in Auckland, New Zealand. Thirteen physicians recruited from a study of family physicians' reported antibiotic prescribing and 13 patients recruited from the intervention arm of a randomized controlled trial on delayed antibiotic prescribing. Patients' and physicians' experiences of delayed antibiotic prescriptions for upper respiratory tract infections. The primary themes identified were value judgments of antibiotics, decreased antibiotic use, patient-centered factors, effects on the physician-patient relationship, patient convenience, adverse effects of delaying prescription, and selectivity for use of antibiotics. Many themes were common to both patients and physicians. Physicians valued empowering patients' decision making about their health care management more highly than did patients. Decreasing antibiotic use was not a key factor for most patients. Both groups acknowledged the value in saving patients time and money. Physicians viewed the strategy as giving patients reassurance and meeting their expectations for antibiotics. Negative implications included perception of physician incompetence and physician loss of management control. Opinions were mixed regarding which patients, under which conditions, were suitable for delayed antibiotic prescriptions. Although delayed antibiotic prescriptions are effective in decreasing antibiotic use for conditions not clinically warranting antibiotics, neither patients nor physicians universally endorsed this strategy. Research to establish formalized recommendations for patient suitability and instructions for use would be of value.