Inonotus obliquus (also known as Chaga) is a fungal parasite of birch trees that has been prized in folkloric medicine for centuries due to its curative powers against cancer and infectious diseases. Over the past decade, a number of studies have examined the anti-tumor properties of various Chaga extracts and demonstrated remarkable efficacy of this natural product in the treatment of solid tumors in mice. We sought to determine if ethanol extracts from Chaga affected the oncogenic properties of cultured melanoma cells. Treatment of B16F1 mouse melanoma cells with fresh ethanol extracts of Chaga resulted in strong increases in melanocyte dendricity as evidenced by increases in the number of cells with dendritic projections, the number of projections per cell, and total projection length. Chaga treatment led to cell cycle disruption as evidenced by decreased steady state cyclin mRNA expression and an increase in the number of cells in the G2 phase of the cell cycle. Moreover, Chaga treatment led to melanoma cell toxicity in a dose dependent manner. These data suggest that ethanol extracts of Chaga may have the potential as an anti-melanoma treatment.