Inspired by natural swarms, micro/nano-scaled agents have been controlled to form micro/nano robotic swarms for biomedical applications. This talk will start with an introduction of the underlying principles of forming and controlling micro/nano swarms, followed by examples of clinical applications. To address clinical demands, we developed micro/nano swarm actuation techniques and functionalization, and validated their therapeutic efficacies in mouse models and large animals. Present embolization techniques are prone to cause unintentional blockage of non-targeted blood vessels due to the lack of selectivity. We proposed a swarm actuation strategy, using thrombin-coated magnetic particles, to realize selective embolization, where the swarms accurately blocked the blood flow inside a targeted region in vivo. Moreover, using magnetic carbon nanotubes (mCNTs), we reported a mechanical nanosurgery approach for treating chemoresistant glioblastoma (GBM), the most common and aggressive primary brain cancer. We functionalized mCNTs with tumor-targeting antibodies to increase their recognition of GBM cells and prolong their enrichment and retention within the tumor. By tailoring tumor-focused magnetic fields, we showed that spatiotemporally controlled mobilization of mCNTs, which functioned as swarms of nano-scalpels, generated mechanical work and induced GBM cell death in vivo.