Electronic personal health records (PHRs) have been gathering interest as a tool for consumers/patients to access and provide input directly to their own health records, thus improving their understanding of the state of their health and helping to streamline their interactions with healthcare providers. This paper reviews the definitions and nature of PHRs and their supporting systems, as found in the current literature. A broad survey of literature covering empirical research into patient and practitioner use of experimental and early implementations of these systems, particularly implications for future system designs, is reported. Topics include: PHR architectures; PHR content; security, privacy and consent; patient information needs and expectations; system design issues; user attitudes, perceptions and experiences; and patient-practitioner messaging. Finally, reports on existing implementations are discussed, followed by a discussion of expected benefits to users and barriers to adoption of PHR systems. The general indications are that there are significant benefits of PHRs, although there are barriers to their widespread adoption due to issues of security and privacy, errors, misdiagnosis and mistreatment, and system costs. Regrettably, consumer/patient motivation for adoption of PHRs has not been considered except in the case of British parents who have been encouraged to create and maintain PHRs for their children, beginning at birth. This is in the face of the likelihood that motivation to adopt and maintain PHRs would be high for parents of children with disabilities, patients with serious chronic illnesses, and caregivers for elderly persons. These potential users would probably be early adopters, if encouraged to do so. Although these population segments do not seem to have been considered specifically yet, they deserve further study since they could provide the impetus for more widespread adoption of PHRs, with attendant benefits to the healthcare system. However, family physicians who actively use EMRs (Electronic Medical Record systems) for the clinical records of their patients tend to play an essential and central role in the implementation of PHRs, so the low rate of EMR adoption by family physicians, except in multiple partner practices, will continue to be a significant overall barrier to PHR adoption in North America for some time.