This review is aimed to summarize current knowledge about endoneurial fibroblasts (EFs) in peripheral nerves and their role in reparative nerve regeneration. Alongside Schwann cells and macrophages, fibroblasts are the most functionally significant cells of the endoneurium. There is limited literature on the characteristics of EFs and their role in the regeneration of injured nerves. This review presents recent data on the morphofunctional features of EFs, their origin during ontogeny, and their functions. It also describes immunohistochemical markers used for their identification. The need to study the interactions between EFs and other nerve cells to elucidate their role in nerve regeneration after injury is particularly emphasized.