Stable and defect-free films are required for many technological applications, while controlled dewetting processes are important for producing thin film microstructuring for microelectronics, optical devices and biochip technology. In this work, we study the dewetting features formed by drying an aqueous solution of a charged polymer deposited on a mica substrate. A rich variety of morphologies can be formed, including holes, polygonal networks, droplets and elongated structures. The dewetting behavior depends on film thickness and on the charge density on the polymer that can be controlled by surfactant addition. The various nanoscale morphological patterns that are formed may be applied as a potential method for surface nanostructuring.