Human follicle-stimulating hormone (hFSH) is a heterodimeric glycoprotein consisting of a common α subunit non-covalently attached to the hormone-specific β subunit. The therapeutic application of this hormone requires large quantities of biologically active contaminant-free hormones. In the current study, secretory expression and purification of codon-optimized recombinant α and β subunits of hFSH were reported using Iranian Lizard Leishmania (I.L.L.) expression system. Synthetic codon-optimized genes of α and β subunits of hFSH were amplified by PCR and cloned into the pLEXSY-hyg2 and pLEXSY-neo2 vectors, respectively. The resulted expression vectors were digested and electroporated into ILL. PCR analysis showed that the genes of α and β subunits of hFSH were inserted into the genome of the parasite. Subunits expression was analyzed by dot-blot and sodium dodecyl sulfate–polyacrylamide gel electrophoresis, and then purified and detected by Western blot analysis. Expression analysis confirmed the presence of protein bands in sizes similar to those of the natural hormone subunits. The low electrophoretic mobility and the apparent higher molecular weight of the expressed subunits were due to successful glycosylation of subunits by ILL expression system.