Toll-like receptors (TLRs) are important players in the innate immune system. Binding of pathogen-related molecules to the extracellular domains of TLRs initiates signalosome assembly, a key event in signal transduction. Despite extensive research on individual receptor domains, the mechanism of signalosome assembly remains unclear. Recent evidence suggests that the intracellular TIR domain of TLR1 binds zinc ions, with cysteines playing a pivotal role in binding and receptor activation. This study explores the zinc-binding ability of the TLR2 TIR domain (TLR2). We found that TLR2 binds zinc with nanomolar affinity through its cysteine residues. Two of them, C673 and C713, are essential for receptor activation. These results suggest that zinc may be involved in the initiation of signalosome assembly.