A solid hollow fiber cooling crystallizer and method for crystallizing aqueous and organic solutions are provided. The solid hollow fiber crystallizer (SHFC) for carrying out cooling crystallization of inorganic/organic microsolutes/macrosolutes from solution generally includes a bundle of non-porous hollow fibers mounted within a shell where a feed solution for crystallization flows through the lumen side of the hollow fibers and a cooling solution flows through the shell side to form nuclei and subsequently crystals in the feed solution at a temperature below its saturation temperature. The solid hollow fiber crystallizer may be combined with a mixing device, such as a completely stirred tank or static mixer, to further effectuate crystallization. The solid hollow fiber crystallizer may be operated in a number of modes including feed recycle mode, once through mode, SHFC-in-line static mixer in series mode, and SHFC-CST in series mode. The advantages of solid hollow fiber cooling crystallization in comparison to conventional crystallization processes include improved temperature control between crystallizing solution and coolant, higher nucleation rates, improved control of crystal size and crystal size distribution, smaller crystal size, capability for decoupling crystal nucleation and crystal growth, decreased fouling of process equipment, and improved process scale-up.