Noncompliance with therapeutic drug regimens is a public health problem with major health and economic implications. Reported rates of noncompliance for all types of drugs range from 13% to 93% among adults and from 25% to 82% among children. In recent years, sophisticated techniques for evaluating noncompliance have evolved, as has our understanding of factors associated with noncompliance. A key factor is the prescribed dosing schedule for a drug. Studies indicate that there is a direct relationship between frequency of dose and compliance. A study of compliance with short-term regimens of oral antibiotic therapy found mean compliance rates of 80%, 69%, and 38% for administration once a day (QD), twice a day (BID), and three times a day (TID), respectively. Pharmacoeconomic analyses of dose-related compliance have demonstrated that significant savings can be achieved with QD dosing of antihypertensive medication. Although similar analyses have not been performed for drug regimens used in the treatment of infectious diseases that are usually treated on an outpatient basis, it is probable that comparable savings will be attained when economic analyses of dose/compliance relationships in short-term antibiotic therapy for such common disorders as sinusitis, pharyngitis, otitis media, urinary tract infections, and community-acquired pneumonia are undertaken.