We report a simple, efficient synthesis of novel (18)F-labeled imaging agents based on YF3 nanoparticles. Targeting ligands and antitumor drug molecules can be introduced onto the YF3 nanoparticles in a one-pot synthesis. The (18)F-labeling reaction proceeds in aqueous solutions at room temperature with excellent radiolabeling yields (>80%) in a very short time (5-10 min). (18)F-labeled YF3 nanoparticles displayed high stability in mouse and human serum, and their application for mapping lymph nodes in live rats after local injection has also been demonstrated.