Vascular changes of the iris were studied in 6 patients with chronic anterior uveitis of varying aetiology by means of fluorescein angiography. In 1 case the angiographic findings of the second eye were compared with the histopathological changes in the fellow eye enucleated earlier because of absolute glaucoma. In the milder cases abnormal superficial vessels were seen mainly in relation to the minor arterial circle of the iris, while in advanced cases a coarse vascular network covered the whole surface of the iris. Both mild and severe changes were found to differ from the arborising type of neovascularisation usually seen in vascular eye diseases. Instead, a resemblance in the vascular pattern was found between some of these cases and eyes with chronic capsular glaucoma. In 1 patient clinical rubeosis seemed to be partly due to dilatation of the pre-existing capillaries rather than true neovascularisation.