Field-theoretic methods are not new to polymer physics. Their basic idea is to replace the particle-based description of the polymer in terms “monomers” or “beads” with a description in terms of collective variables, or fields (e.g. “density field” or “charge field”). Even the lowest order of this approach – the mean-field approximation – has already produced some remarkable results, most notably for block copolymers. However, for certain polymer systems, such as polyelectrolytes, the mean-field approximation in most cases produces trivial results, and fluctuations must be taken into account. Recent developments in analytical and numerical field-theoretic techniques allowed a new, “beyond the mean field”, level of description of such strongly correlating systems as polyelectrolytes. I will provide a very basic introduction to the field-theoretic approach to polymer systems and illustrate this approach by our recent results for polyelectrolyte solutions.