Terahertz (THz) shielding effectiveness (SE) of nickel nanochains (NiNC), multiwalled carbon nanotubes (MWNT) and their composites in poly-vinyl alcohol have been studied in the frequency range of 0.4-1.8 THz at room temperature. NiNC of diameter ~ 300 nm and length ~ 4 μm are synthesized by reducing nickel chloride salt with hydrazine hydrate in ethylene glycol medium. NiNC and MWNT+NiNC composites show 130% and 260% increased SE at 1 THz than MWNT composites, respectively. Such a large increment in SE depicts that NiNC can easily replace the universally known MWNT composites as cost effective materials with higher shielding efficiency for the applications in THz shielding devices.