The tissue microarray (TMA) technique is a 'high-throughput' tool which enables a rapid and concurrent analysis of molecular targets in large numbers of specimens at the DNA, RNA and protein levels under standardized conditions. In addition, TMA is a cost- and time-efficient method. This review focuses on its technical side, outlining its advantages and weaknesses. It also gives an overview of some major studies of bladder and prostate cancer in which the TMA technique was used.