Experimental and clinical evidence suggests that tumour angiogenesis plays a role in the tendency for certain neoplasms, including cutaneous melanomas, to metastasize. We evaluated whether tumour vasculature is associated with the rate of metastases in patients with melanoma of the choroid or ciliary body. The study was based on a group of 63 patients enucleated between 1976 and 1984 with paraffin-embedded tissue blocks available for sectioning and with known survival status as of December 1988. Vessel endothelial cells were highlighted with Ulex europaeus agglutinin I (UEA-I) conjugated with peroxidase. UEA-I-stained microvessels were counted at varying levels in the tumour (apex, centre and base) without knowledge of patient outcome. Patients with (n = 30) and without (n = 33) metastases had similar total vessel counts (P = 0.31). There was no evidence of greater vessel density in tumours that had metastasized, by level within the tumour. Similar results were obtained in multivariate analyses. Findings of this study suggest that tumour microvessel density is unrelated to patient survival in uveal melanoma.