We developed a multifunctional polymer coating for nanoparticles (NPs) that enables simultaneous detection by 19F MRI and shielding from blood plasma fouling. The coating is based on a water-soluble fluorinated poly(N-(2-fluoroethyl)acrylamide) (PFEAM) that shows high 19F MRI sensitivity, cytocompatibility and excellent antifouling properties, significantly outperforming polyethylene glycol. A proof-of-concept experiment was performed by synthesizing polymer-coated gold NPs that were successfully visualized by 19F MRI at magnetic fields close to the fields used in clinical practice. This universal approach can be used for coating and tracing of various NPs upon suitable polymer chain-end modification.