Polyacrylonitrile (PAN) and PAN/carbon nanotube (CNT) composite fibers have been processed using gel spinning. Tensile strength and tensile modulus of these gel spun fibers can be higher than 1.0 GPa and 25 GPa, respectively. These fibers have been stabilized in the temperature range of 175 to 350 oC and carbonized in the temperature range of 600 to 1500 oC. Fibers carbonized in the 1100 to 1300 oC exhibit tensile modulus as high as 600 GPa and tensile strength as high as 6 GPa. These studies were carried out in batch processing mode, where residence time for carbonization was several hours. It is expected that in continuous processing, where much shorter residence time can be used, substantially higher tensile strength can be achieved than obtained from batch processing. Results of PAN/CNT solution spinning, gel spinning, as well as their stabilized and carbonized products are briefly reviewed here.