The translational enhancement of the 5′-leader sequence of the tobacco mosaic virus (TMV) and tobacco etch viral 5′-leader sequence (TEV) was compared in relation to the expression of the human calcitonin (hCT) gene in transgenic potato plants. The synthetic human calcitonin tetrameric genes were cloned under the control of the 35S Cauliflower mosaic virus (CaMV)promoter linked to the TMV or TEV leader sequences. The resulting constructs were cloned into the binary vector Bin19 and potato minituber discs transformed using an agrobacterium strain. The expression of the hCT gene was studied by mRNA-DNA hybridization, a RT-PCR, ELISA and RIA. The results showed that the TMV omega element increased the yield of the expressed recombinant protein two to three-fold in comparison with the TEV leader sequence.