The aim was to investigate the content of 4- and 6-sulphated glycosaminoglycans (GAGs) in specimens from temporomandibular joint disc and posterior disc attachment in patients with painful clicking and chronic closed lock. Nineteen patients (19 joints) with a clinical diagnosis of painful clicking were compared with 22 patients (22 joints) with a clinical diagnosis of chronic closed lock. Specimens were obtained from the disc and the posterior disc attachment, and their content of glycosaminoglycans analysed by means of capillary zone electrophoresis. These were significant differences in the amount of glycosaminoglycans between the two groups, values in patients with painful clicking being comparable to those of normal individuals, while patients having chronic closed lock showed significantly reduced values. Both groups showed higher values in the posterior disc attachment when compared to the disc and similar pattern of glycosaminoglycan sulphation. The results suggest that these two patient groups have distinctly different patterns of tissue reactions. In patients with chronic closed lock there was an altered composition of matrix, this change involving both disc and posterior disc attachment.