In this report the zone-melting Czochralski (ZMCz) growth of Bi12SiO20 (BSO) single crystals is presented and its growth stability is discussed. With a careful starting up of the melt level, the growth was found always self-stabilized leading to an excellent diameter control. Due to the zone-leveling nature, the grown crystals showed good optical uniformity. Nevertheless, it was found that bubble inclusion was a serious problem. By using an inner crucible, bubble-free crystals could be easily grown. This double-crucible ZMCz technique was found to be useful and could be used for other oxides as well. (C) 2002 Elsevier Science B.V. All rights reserved.