Asymmetric hollow fibers comprising a fluoropolymer, and a process for making such fibers. The hollow fibers are useful for making fluid separation membranes, especially gas separation membranes. In one embodiment of the process of this invention, a polymer dope having a viscosity of about 3000 poise or greater is prepared by solvating the polymer in a solvent system containing about 40%-90% N-methyl-2-pyrrolidone and about 60%-10% propionic acid by weight. The dope is dry-jet wet-spun into hollow fibers using a water-NMP core solvent. The fibers are coagulated in methanol. The fibers are then coated with a highly permeable material.