In this paper, we demonstrate the production of highly magnetic and fluorescent giant vesicles by encapsulating gamma-Fe2O3-rhodamine B nanoparticles. The liposomes containing the nanoparticles were made of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC). We found that the ionic strength of the initial magnetic fluid is a crucial parameter in controlling the physicochemical properties of the bilayer. At high ionic strength, we obtained very important deformations of liposomes with high magnetic susceptibilities induced by an applied magnetic field. The encapsulation rate was studied using magnetophoresis and photobleaching tests, and the membrane properties were studied using confocal microscopy and elastic measurements.