The synthesis of a novel and specific nanoplatform for anticancer drug delivery, fluorescence imaging and contrast agent in magnetic resonance imaging has been described. Hierarchical theranostic hollow magnetic mesoporous spherical particles with fluorescent carbon encapsulated within the mesoporous framework have been prepared by the hydrothermal carbonization approach. These particles show MR contrast behaviour by affecting the proton relaxation with transverse relaxivity (r2) of 150.05 mM-1 S-1. These multifunctional fluorescent magnetic nanoparticles have been conjugated with the hydrophobic drug, camptothecin, and a molecular marker, folic acid, using appropriate surface chemistry. The drug-conjugated hybrid nanoparticles inhibit cell growth through the induction of apoptosis as demonstrated in HeLa cells.