This review summarizes the recent developments in fluorescent conjugated polyelectrolytes (CPEs) in bioimaging. The CPEs discussed include linear-, hyperbranched-, and polyhedral oligomeric silsesquioxanes (POSS)-based derivatives. Originating from their special optical properties, good photostability, low cytotoxicity, ease of bioconjugation and tuneable size, CPEs have shown wide applications in in vitro and in vivo protein and cell imaging, drug tracking and gene delivery. Moreover, some CPEs also possess antibacterial and anticancer characteristics as well as apoptosis imaging functions. Finally, this review discusses the future outlook of CPEs in bioimaging applications.