Heterologous gene expression in mammalian cells is the first choice for the production of recombinant proteins when posttranslational modifications affect the biological activity of target proteins. However, the expression efficiency of mammalian cells is relatively low compared to other expression systems, such as Escherichia coli or yeast. Recently, a novel protein expression system based on Leishmania tarentolae , a protozoan parasite of gecko, was developed. This system allows not only easy handling like E. coli and yeast, but also full eukaryotic protein folding and the mammalian-type posttranslational modifications of target proteins. Here, we attempt to produce recombinant human laminin (LM)-332, a large heterotrimeric glycoprotein, in the L. tarentolae expression system. A recombinant strain harboring three subunits of LM-332 efficiently formed a heterotrimer and secreted it into the medium. The purified rLM-332 showed similar cell adhesion activity to rLM-332 purified from mammalian cells, indicating its proper folding and assembly. In this chapter, we describe a detailed protocol for multiple gene expression in the L. tarentolae expression system.