In 1993 a special Early Arthritis Clinic (EAC) was established at the Department of Rheumatology of the Leiden University Medical Center in order to detect and treat inflammatory disorders early in the disease state, especially early rheumatoid arthritis. Patients with confirmed arthritis of recent onset (less than 2 years) were included by rheumatologists and trained research nurses. Parameters of first and follow-up visits (3, 6 and 9 months and yearly) that were entered in the EAC-database include the medical history, physical-diagnostic examination, laboratory tests, questionnaires, radiographic joint scores and diagnosis. This database enables us to conduct research on arthritis, with an emphasis on rheumatoid arthritis, in many ways. Physicians and basic scientists have studied cellular immunology and genetic, environmental and clinical risk factors in order to determine the pathophysiologic mechanisms of inflammatory arthritis. The present article is a review on reports published from the EAC. Over the past ten years, these reports have been highly relevant for both daily clinical practice and research. Present and planned future studies, as described in this article, reconfirm the importance of an EAC framework to ensure that research continues on this disease in the Leiden EAC area.