Dapper (Dpr)/Frodo/Dact family, a recently discovered protein family in vertebrates, consists of three members, Dpr1-Dpr3. Although Dpr family members share low levels of amino acid sequence identity, they appear to act as scaffold proteins to modulate Wnt and other signaling pathways. All of the known Dpr proteins have been found to regulate canonical and/or noncanonical Wnt signaling by physically associating with Dishevelled. Dpr2 has also been shown to control TGF-b signaling by binding to and promoting the degradation of the receptors ALK4/5. Dpr genes are expressed in specific domains of vertebrate embryos and in distinct tissues and organs in adults. Recent studies have demonstrated that Dpr genes are implicated in axis formation, mesoderm induction, embryonic cell movements, adipogenesis, keratinocyte migration, and tumor development. In this review, we summarize recent advances in understanding the roles of Dpr proteins in signaling transduction and vertebrate development.