Electronic Health Record (EHR) is a distributed system that results from the cooperation of several heterogeneous and autonomous subsystems. It improves health care by enabling access to prior diagnostic information to assist in health decisions. We focus on the image and imaging report visualization component that needs to interoperate with several other systems to enable healthcare professionals visualize a patient's imaging record. We propose and describe an environment that has been built and used to facilitate the development of the viewer component. This environment has also been used to test and verify the interoperability of the viewer component with other EHR components in accordance with the Integrating the Healthcare Enterprise (IHE) technical framework. It has also been used to demonstrate functionalities, to educate end users, and to train maintenance and test engineers. Moreover, it has been used for acceptance testing as part of an EHR deployment project. We also discuss the challenges we faced in constructing the testing data and describe the software developed to automatically populate the test environment with valid data.