This paper discusses various field theories for polymer systems. The starting point is the connection of the Gaussian random walk with the Gaussian model in statistical field theory. We briefly review the extension to self avoiding walks. Two alternative field theories exist, i.e. a bosonic field theory and another one using anticommuting fields. It is shown that these two formulations present a sound basis for the description of conducting polymer chains, which are described by means of a Hubbard model. The electrons are constrained to hop along the chain contour only. It is therefore obvious that two anticommuting variables are necessary to describe the physical system: The disorder due to the conformational polymer field and the creation and annihilation of the electrons on various contour points along the chains.