Polycrystalline ZnO nanowires have been . grown in anodic aluminum oxide templates using a dry vapor-deposition method. The nanowires have a high aspect ratio and a uniform density of 10(10)-10(11).cm(-2) over a large area (similar to20 mm(2)). Room temperature photoluminescence measurements show lasing modes between 381 and 389 nm above a threshold power density of 100 kW/cm(2) (see Figure).