Early diagnosis is being appropriately emphasized in RA, as early DMARD treatment can be very effective. ACR criteria are useful but may not perform as well in early disease. These criteria depend on clinical examination, which is subject to over- and under-interpretation. Ultrasound and MRI may offer advantages. Laboratory tests and synovial fluid analyses may contribute, but are often not definitive. All of these data, synovial biopsies and a variety of other features can guide prognosis as well as diagnosis. Consideration of the whole patient, including education levels and coping strategies, can help. Aggressive management is proposed for most patients once the diagnosis is firm. Strategies are needed to arrange that patients are seen at a very early stage by rheumatologists knowledgeable in the treatment of early arthritis. Early diagnosis is receiving increasing emphasis in RA, with the recognition that erosive irreversible disease can occur in the first months and that a variety of treatments can clearly prevent or slow disease progression (1, 2). Most studies addressing early RA use the American Rheumatism Association (ARA), now the American College of Rheumatology (ACR), criteria (3) for purposes of uniformity although these criteria have been shown to be less valid in early disease (4). Early DMARD treatment can make a difference, but there are a number of unanswered or partially answered questions about diagnosis that remain to be addressed. We review this area, focusing on work from our own research and how this has guided our thinking.