The healthcare model currently being used in most countries will soon be inadequate, due to the increasing care costs of a growing population of elderly people, the rapid increase of chronic diseases, the growing demand for new treatments and technologies, and the relative decrease in the number of healthcare professionals with respect to the population increase. This healthcare model, which is centered on highly specialized people, located in large hospitals, needs to change into a distributed model, in order to produce faster responses and to allow patients to manage their own health. This centralized healthcare model also implies that patients and healthcare professionals have to move to the same place (a hospital or clinic) for the healthcare services to be delivered, and it is often expensive and inefficient. A distributed healthcare model that pervades the daily lives of the citizens is more appropriate to provide less expensive and more effective and timely healthcare, and characterizes Pervasive Healthcare. In Pervasive Healthcare, novel information and communication technologies are applied to support the provision of health services anywhere, at anytime and to anyone.This thesis aims at demonstrating the feasibility of using healthcare standards, ubiquitous computing technologies, service-oriented architecture principles, and software agents, to develop interoperable applications for exchanging messages in Pervasive Healthcare environments. This thesis presents a Reusable Architecture and a Message Generator that employ these technologies for achieving its aim. Our Reusable Architecture and Message Generator also meet the requirements of interoperability between heterogeneous healthcare information systems that are usually found in Pervasive Healthcare environments.In this work, a case study was performed in a realistic distributed healthcare environment, where three usage scenarios were defined in the cardiology domain: delivery of laboratory analysis results, schedule of an appointment for pacemaker evaluation, and support of a medical staff II ABSTRACT meeting to prepare for a cardiac surgery. Using the Reusable Architecture and the Message Generator, three applications were built for these scenarios, and they were employed and evaluated by both healthcare professionals and patients. The experiments were conducted in a distributed environment that consists of three cardiology clinics, one analysis laboratory, and the cardiology department of the Santa Casa Hospital of Marília (São Paulo, Brazil). The evaluation of these applications was carried out using the Technology Acceptance Model (TAM), since this model is generally considered as appropriate to explain technology acceptance. The evaluation involved a limited but representative set of healthcare professionals and patients.We showed that the methodology proposed in this thesis truly facilitates the development of Pervasive Healthcare. The proposed methodology preserves the investment in the legacy healthcare information systems and allow...