We have fabricated GaN quantum dots (QDs) embedded in an AlGaN matrix on a uniform array of hexagonal pyramids of GaN, using metalorganic chemical vapor deposition with selective growth. Hexagonal pyramids of very sharp apices were realized. The radius of curvature at the apices was no more than 10 nm as shown by cross-sectional scanning electron microscopy. Intense photoluminescence from GaN QDs was observed at the peak wavelength of 343.5 nm at room temperature. (C) 2002 Elsevier Science B.V. All rights reserved.