Transition metal dichalcogenides (TMDs) have attracted great interest owing to their fascinating properties with atomically thin nature. Although TMDs have been exploited for diverse applications, the effective role of TMDs in synthesis of metal nanowires has not been explored. Here, we propose a new approach to synthesize ultrathin metal nanowires using TMDs for the first time. High-quality ultrathin nanowires with an average diameter of 11.3 nm are successfully synthesized, for realizing high performance transparent conductor exhibiting excellent conductivity and transparency with low haze. The growth mechanism is carefully investigated using high-resolution transmission electron microscopy, and growth of nanowires with tunable diameters is achieved by controlling the nanosheet dimension. Finally, we unravel the important role of TMDs acting as both reducing and nucleating agents. Therefore, our work provides a new strategy of TMD as an innovative material for the growth of metal nanowire as a promising building block in next-generation optoelectronics.