A novel non-aggregating polypyrene, which can be synthesized via a simple three-step chemical route from pyrene in good yields, is presented. Poly-7-tert-butyl-1,3-pyrenylene shows a high solid-state fluorescence quantum yield with blue emission, excellent solubility and stability, no aggregation in thin films, and good electro-optical performance in single-layer organic light-emitting diodes (see figure).