Sixteen patients with painful tender swelling in the region of the sternocostal joint (SCJ) are reported and analysed against the background of a review of 106 previously reported patients with Tietze's syndrome. Seven patients fulfilled all the diagnostic criteria for Tietze's syndrome. The radiographic findings and/or the history of these patients suggested that local strain generated by respiration is a pathogenetic factor. Nine patients had a systemic arthritic disorder, skin disease, or psoriasis in their family. They differed from the 7 patients with local involvement and from those reviewed, by the rather frequent bilateral involvement, a frequent affection of the first SCJ and the manubriosternal joint, and a female predominance. Their SCJ swellings may be viewed as part of a seronegative arthritis.