Different polyurea-amides were synthesized by interfacial polymerization of acid chloride, diamine, and diisocyanate. The polymers and the membranes were characterized for their RO/UF applications. Highly porous membranes could be prepared from the sulfuric acid-based casting formulation and the membrane casting conditions were established. The resulting membranes are not asymmetric as they give high permeability to water and salt solutions. They are found to be resistant to many organic solvents, thus making them useful in concentration/separation applications. Whole milk, egg albumin and Na-alginate were found to be rejected 100% by these membranes, while solutes of about 20,000 Mw are found to be rejected to the extent of 70-80%.