For tissue diagnosis in patients with abnormalities of various organs, endoscopic ultrasonography (EUS)-guided fine needle aspiration (EUS-FNA) has emerged as an effective technique. Subsequently, EUS-guided fine needle injection (EUS-FNI) has expanded the clinical utility of EUS. Several applications of EUS-FNI for anti-cancer efforts have included celiac nerve blocking and drug delivery into tumors, such as ablation, chemotherapy, gene therapy, and cytoimplantation. Furthermore, chemosensitivity tests with materials obtained using EUS-FNA are available to produce tailor-made medicines. Demonstrably, EUS-guided intervention has opened new and exciting clinical applications for the management of malignancies.