Sulfides, such as Na₂S and NaHS, enhance Ca_v3.2 T-type Ca²⁺ channel activity, thereby promoting pain signals. We hypothesize that, as does L-Cys, a thiol compound, sulfides might interact with zinc binding to His-191 in Ca_v3.2 and cancel the zinc-induced channel inhibition. On the other hand, the effects of polysulfides, such as Na₂S₃ and Na₂S_4, on Ca_v3.2 function have yet to be investigated. Thus, we compared the effects of sulfides and polysulfides on T-channel-dependent currents (T-currents) in human Ca_v3.2-expressing HEK293 cells, and analyzed possible involvement of sulfide-zinc interaction. Na₂S and NaHS at 3-30 µM rapidly caused remarkable and persistent increase in T-currents. In contrast, Na₂S₃ and Na₂S₄ in the same range caused only slight and transient T-current increase, followed slowly by its decrease below the baseline. In the presence of tricine, a weak Zn²⁺ chelator, T-currents increased, which was reversed by ZnCl₂ at 30 µM. The increased T-currents in the presence of tricine was not altered by Na₂S at 30 µM, but augmented by addition of Na₂S following ZnCl₂. Our data suggest that the sulfide-induced enhancement of Ca_v3.2 function involves the interaction of sulfide with Zn²⁺ possibly binding to His-191 in Ca_v3.2, and cannot be mimicked by polysulfides.