Ultrafiltration (UF) membranes of six selected poly(amidesulfonamide)s (PASAs) were prepared and studied. The pure water flux and the retention of albumin (bovine serum) were used to evaluate the quality of the UF performance of the fabricated membrane. Membranes with good mechanical strength were obtained by using the phase inversion method. A comparison of the UF performance of the PASA membranes fabricated from a casting solution containing 12% w/w PASAs and 4% w/w lithium bromide in dimethylacetamide was made. The best retention of albumin (bovine serum) by membranes prepared under the conditions studied from the selected homopolymers of PASAs, and their corresponding pure water flux at 0.207 MPa, ranged from 84.6 to 100% and 120 to 396 L m(-2) h(-1), respectively.