The self-organization of water-soluble endometallofullerenes (fullerenols) in solutions has been studied by neutron scattering in connection with their applications (Magneto-Resonance Imaging, X-Ray Tomography). Their functional characteristics depend strongly on molecular self-assembly which may be altered by chemical additives, concentration increase or the magnetic field applied. Polarized neutrons have been used to search paramagnetic fullerenols’ organization into supramolecular structures influenced by the fullerenol concentration and their intensified interactions in a magnetic field.