Glechoma hederacea L. (Labiatae) has been used in folk medicine to treat various ailments for centuries. We investigated the effects of G. hederacea extract on melanogenesis in B16 melanoma cells. It significantly reduced both the cellular melanin content and tyrosinase activity in a concentration-dependent manner. An MTT assay did not reveal any obvious cytotoxicity. Furthermore, we found that G. hederacea extract decreased tyrosinase and microphthalmia-associated transcription factor protein expression, but did not inhibit tyrosinase-related protein-1 and tyrosinase-related protein-2 expression. RT-PCR analysis indicated that the antimelanogenic effect of G. hederacea extract might be due to inhibition of tyrosinase gene transcription. Moreover, this effect is regulated via suppression of microphthalmia-associated transcription factor protein expression. Our data indicate that G. hederacea extract inhibits melanin synthesis in B16 melanoma cells but is not cytotoxic. Hence it might prove a useful therapeutic agent for treating hyperpigmentation and an effective component of whitening cosmetics.