Determining the number of swollen joints and tender joints is a key component in the clinical assessment of rheumatoid arthritis (RA). There have been a series of investigations carried out in the last decade, which have defined the best ways to measure joint inflammation and have identified which joints should be evaluated. There is not complete agreement on the optimal joint count, but two approaches are widely used. These comprise counting either 66/68 or 28 joints. The main difference is that the 28-joint count excludes the joints in the feet. Both methods give similar information and are reproducible and valid. Tenderness and swelling should be measured separately. There are advantages and disadvantages associated with using the 28-joint count It has the benefit of simplicity and takes less time, although some potentially relevant clinical information about the feet may be lost There is general agreement that grading the severity of individual joint involvement is of limited advantage. Using weighted joint counts is also not widely accepted. Finally there is growing recognition of the need for training in the methods of assessing joints and the importance of international standardization. Joint counts are a component of the core clinical data set for RA and will continue to play a key role in the foreseeable future.