Pancreatic cystic neoplasm (PCN) is a category of pancreatic tumors with significant heterogeneity. In recent years, the detection rate of PCN has been increasing, and it has gradually become a concern of clinicians. Endoscopic ultrasound (EUS) can be close to the pancreas for scanning and biopsy, and it has certain advantages in the diagnosis and treatment of PCN. This review mainly summarizes the latest progress of EUS in the diagnosis and treatment of PCN. Cyst fluid molecular markers, such as Kirsten rat sarcoma viral oncogene homolog, GNAS complex locus, Von Hippel-Lindau tumor suppressor gene, as well as emerging endoscopic technologies such as EUS-guided needle based confocal laser endomicroscopy and through-the-needle biopsy, have all showed the potential to significantly improve the diagnostic accuracy of PCN. EUS-guided ablation is an emerging minimally invasive treatment technique for PCN, with the efficacy and safety of chemical ablation being supported by a substantial amount of research.