Electronic Medical Records (EMR) systems offer health care organizations numerous potential benefits. However, it can be difficult to ascertain whether users are satisfied with such systems, and if not, where concerns exist. Organizations wishing to evaluate a health care system implementation like an EMR system can choose from a variety of approaches that have been developed in the Information Systems (IS) discipline. After evaluating a number of alternatives, the researchers selected the Task Technology Fit (TTF) model and its associated instrument as a diagnostic tool to evaluate the implementation of the first phase of an EMR at a university hospital. A survey was administered and an analysis of the data found that the EMR system users, both physicians and nurses, were generally very pleased with the EMR implementation, and, therefore, it could be deemed a success. Based upon this study the TTF model and its associated instrument appears to be a useful diagnostic tool for evaluating a health care information systems implementation.