The micro-pulling-down growth and characterization of Bi4Si3O12 and Bi4Ge3O12 fiber crystals for scintillation applications are reported. The diameter of the crystals varied from 0.1 to 1.0 mm. The results demonstrate that this technology is suitable for development of miniature imaging sensors particularly for the application in Positron Emission Tomography. The crystals were produced from the crucibles that had different shapes of the die: conventional tubular one and that made of two parallel plates with the melt sited between the plates (double-plate die). The quality of the crystals is discussed based on backscattered electron imaging results. Basic scintillation performance was tested in order to evaluate the scintillation efficiency of BGO and BSO fiber crystals coupled to a photomultiplier tube. (C) 2007 Elsevier B.V. All rights reserved.