The evolutionarily conserved and developmentally important Wnt signaling pathway has traditionally been regarded as a critical player in tumorigenesis through the canonical Wnt/beta-catenin cascade. Nevertheless, accumulating evidence based on recent research has revealed the previously unacknowledged role of noncanonical Wnt/planar cell polarity (PCP) signaling in cancer progression, invasion and metastasis, and angiogenesis. This review describes the PCP signaling pathway and its ever-expanding components and modulators, highlights the most recent studies that provide insight into the link between PCP signaling and cancer, and, finally, proposes a model by which PCP signaling may promote cancer development. This review underscores the emerging theme that deregulated PCP signaling contributes to tumorigenesis, providing new potential targets for cancer therapy.