Telephone calls have become the primary mode of communication between patients and physicians outside of the office setting. The telephone's importance primarily revolves around its potential to improve physician practices and augment the physician-patient relationship by positively affecting clinical outcomes and overall patient satisfaction. Specific interactions between the physician and patient are termed "encounters"; calls between physician and patient can only be considered "clinical telephone encounters" if they are documented with appropriate elements of a face-to-face encounter, to include history and clinical decision-making. In this thesis, we explore current literature in order to identify how clinical telephone encounters are defined, barriers to gathering data on the telephone, telephone encounter documentation methods, patient and physician perspectives of telephone encounters, telephone encounters in practice, as well as the major areas for improvement in telephone medicine. We utilized traditional systematic search methods in order to identify original research studies and systematic reviews that evaluate telephone communication's role as a medium of healthcare delivery. In reporting on the effectiveness and utilization of telephone care, we principally rely on evidence provided by randomized controlled trials, controlled before-and-after studies, and guidelines published by leading authorities on telephone medicine. The results show a three-function model to frame the telephone interview, which involves determining the problem's nature, developing a therapeutic relationship with the patient, and simultaneously educating the patient while implementing the appropriate treatment plan. Several studies have outlined the importance of documenting clinical telephone encounters, including the highlighting of legal issues pertaining to the practice of medicine, the establishment of clear communication with the primary care physician, and the demonstration of any potential abuses of the system. In practice, studies observing telephone follow-up of cardiac care after either myocardial infarction or surgery demonstrated improved behaviors and patient outcomes, including low-density lipoprotein cholesterol lowering, smoking cessation, improved exercise capacity, and the ability to return to normal activity in a more rapid manner. Telephone encounters may also prove to be appropriate for many acute disorders, respiratory tract infections, and common symptoms. The results also indicate that charging for telephone calls may cause patients to value calls more, changing their views on telephone encounters from favors by the physician to professional treatment. Additionally, the consequences of errors in practicing telephone management have the potential to be severe; from a medicolegal standpoint, telephone patient contacts do not differ from office visits in terms of physician-patient obligations. Finally, training physicians to be competent in telephone medicine is critical, for studies have shown that they tend to consider themselves incompetent at the task. The literature has also shown that providing patient care over the telephone has proven to be an integral part of practicing medicine and requires familiarity (and even mastery) of specific skills. Telephone care has the potential to substitute for office visits under very certain circumstances. Our review also suggests limitations in the overall literature include the consistent quoting of a survey of how many residency programs teach telephone medicine in their curriculums. For example, the number (6%) that is consistently quoted is from a survey taken in 1995. Further studies should be done to determine whether that statistic has improved or changed dramatically in the nearly 20 years that have passed since that survey. Finally, there are many questions regarding telephone medicine's future. It is very likely that the volume of telephone calls between physicians and patients will continue its current growth trends, which necessitates maximal efficacy and efficiency of calls while ensuring cost-effectiveness and reduction. Disease-management strategies, created to empower patients with the ability to self-monitor, may result in more calls regarding the management of chronic illness. Additionally, cost-reduction strategies such as replacing scheduled visits with telephone calls may become the convention.