Nanofiltration Membranes (NF) contain nanometer pores to selectively separate divalent ions and organic species from water. These membranes are most often made of polymeric thin films and are used in water softening applications to remove scale forming ions. NF membranes which can survive in harsh conditions such as acidic environments have drawn interests in the industry. Acid resistant nanofiltration membrane (ARM) was fabricated using interfacial polymerization reaction of a specially formulated monomers on a support layer. ARM showed durability in acidic environments. As compared to NE40, ARM showed little change in flux and divalent ion rejection after being exposed to 15% sulfuric acid solution for 30 days. The ARM showed stable performance in comparison to regular NF membranes, losing both flux and rejection.