Gold(I) complexes containing N-heterocyclic carbene ligands were synthesized, characterized, and along with the antiarthritic drug, auranofin, tested as inhibitors of the cysteine-dependent protein tyrosine phosphatases, which are implicated in several disease states. These compounds exhibit potencies in the low micromolar range against the enzymes in vitro. At therapeutically relevant concentrations, all compounds inhibit PTP activity in Jurkat T leukemia cells with some selectivity. In addition, the gold-carbene compounds inhibit phosphatase activity in primary mouse thymocytes.