Stability of the solution against spurious nucleation plays a dominant role in the growth of crystals at high growth rates requiring high levels of supersaturation. If any spurious nucleation does occur during a growth run, it becomes practically impossible to grow a very large crystal. A novel nucleation-trap crystallizer has been developed and used for the growth of crystals from aqueous solution so as to trap any unwanted nuclei and the particles that appear and settle at the bottom of the crystallizer during the growth process. In this crystallizer, any particles and nuclei nucleating during the growth are forced into the nucleation trap (or well) and subsequently by manipulating the temperature of the well; the growth of the nuclei is arrested. DKDP and ammonium acid phthalate crystals were grown in the developed system. X-ray rocking curve measurements on DKDP and ammonium acid phthalate crystals yielded FWHM of 89.1 and 29.71 arcsec, respectively. (c) 2006 Elsevier B.V. All rights reserved.