We present the fabrication of parylene-based hollow nanomechanical resonators, following a simple two step fabrication process with a thermal budget of less than 120°C. This process is ideal for fast prototyping and compatible with most materials used in micro- and nano-fabrication. In particular, the example we present here shows a hybrid structure with silicon nitride and parylene, but we have also demonstrated compatibility with metallic electrodes and aluminum nitride piezoelectric layers.