The aim of the study was to evaluate the expression of cell proliferation markers (PCNA and Ki-67) in posterior uveal melanomas in adults. Thirty-six enucleated eyes (without prior treatment) were included in histopatological study. A series of 15 cases of spindle cell type melanomas, 12 epithelioid and 9 of a mixed type were assessed, using the immunohistochemical method with monoclonal PCNA and Ki-67 antibodies. PCNA expression was observed in 75% and Ki-67 in 13.8% of all the examined tumours. The mean score of PCNA and Ki-67 index were the highest in tumours, which contained epithelioid cells and in large, more advanced (pT3, pT4) uveal melanomas. The results showed that the evaluation of expression of PCNA and Ki-67 may provide an additional infonnation about the progression of tumor process.