Recent research has focused on the role of growth factors in flexor tendon wound healing. These basic science reports have described the identification and quantification of various growth factors in in vitro and in vivo models. Although these reports have begun to piece together the cascade of events involved in flexor tendon wound healing, the clinical relevance for the practicing hand surgeon is unclear. Growth factors are cell-secreted proteins that regulate cellular functions. These growth factors are involved in cell differentiation and growth, including the normal processes of development and tissue repair. Several growth factors recently have been identified as playing roles in tendon healing including vascular endothelial growth factor (VEGF), insulin-like growth factor (IGF), platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF), and transforming growth factor beta (TGF-beta). In addition, the transcription factor NF-kappaB has been implicated in the signaling pathways of these growth factors. The purpose of this article is to describe what is known about the molecular basis of flexor tendon wound healing, to review the most commonly studied growth factors, and to summarize likely clinical applications of these growth factors to flexor tendon repair.