l-Asparaginase (EC3.5.1.1)is animportantmedical enzyme that catalysis thehydrolysis of l-asparagine to aspartic acidandammonium. For over fourdecades l. asparaginaseutic agentfor the treatment of a variety of lymphoproliferative disorders and lymphoma such as acute lymphoblastic leukemia. In the present study A. terreus full length l. asparaginase gene, 1179 bp was optimized for expression in Escherichia coli BL21 (DE3) pLysS. The full length A. terreus l. asparaginase gene encoding a protein of 376 amino acids with estimated molecular weight of 42.0 kDa and a theoretical isoelectric point (pI) of 5.0. BLAST and phylogeny analysis revealed that the A. terreus l. asparaginase shared high similarity with other known fungal l. asparaginase (75% homology with A. nomius and 71% with A. nidulans). The recombinant protein was overexpressed in the form of amorphous submicron proteinaceous inclusion bodies upon induction with 1 mM IPTG at 37 ◦C for 18 h.