Bacterial infections have become one of the greatest threats to human health. The emergence of drug-resistant bacteria poses an urgent need to avoid bacterial resistance and sterilize bacteria. The fluorescence technology for the detection and image-guided therapy has attracted considerable attention. However, traditional fluorescent dyes suffering from aggregation-caused quenching are not suitable for biomedical applications. Aggregation-induced emission luminogens (AIEgens) that display strong emission in aggregated states, low background, high signal-to-noise ratio and sensitivity, and high resistance to photobleaching, may circumvent this problem. On the other hand, the overuse of anti-bacterial antibiotics diminishes their effect. It is imperative to develop novel antimicrobial approaches that could effectively avoid bacterial resistance. The development of AIEgens for bacterial detection and theranostics has recently caused a lot of concern, which is ascribed to their remarkable advantage compared with traditional organic fluorescent probes. The application of AIEgens in bacterial detection and treatment in the past five years was reviewed in this paper, including advancements in the development of versatile AIEgens for bacteria imaging, detection, and potential clinic therapy.