There has been much discussion of the role that recent advances in information and communication technologies (ICTs) could play in improving health systems in developing countries, but limited independent analysis of existing applications. Combining a case study approach with a general discussion of the issues, this paper attempts to assess the potential benefits of a diverse range of ICT innovations and some of the constraints they will need to overcome. Four broad areas are considered: improvements in traditional health information systems; computer-aided diagnosis and treatment monitoring; a range of applications generically labelled 'telemedicine'; and the use of ICT to inform general populations on health and healthcare. The final section speculates on the possible medium-term impacts of ICT in terms of improving the performance of existing systems, allowing scope for radical innovations, or even changing basic assumptions about the provider-patient relationship.