A system for the production of soluble interferon (IFN)-lambda 2 was developed by fusing the IFN-lambda 2, NusA protein, polyhistidine and S peptide genes and then expressing the fused product (Nus-His-S-tagged IFN-lambda 2) in Escherichia coli. The expressed fusion protein was purified by Ni-NTA affinity chromatography. The fusion tag was removed from recombinant IFN-lambda 2 by cleavage with enterokinase. N-Terminal sequencing confirmed the identity of the purified protein. When compared with commercial IFN-alpha 2b, IFN-lambda 2 had similar antiviral activity. The production and characterization of biologically active IFN-lambda 2 will be beneficial for its potential role in clinical applications.