An efficient and easy recyclable heterogeneous oxidation catalyst was prepared by grafting TEMPO–NH2 moieties on the surface of magnetic multi‐walled carbon nanotubes (MWCNT), first by a radical reaction introducing butyric acid moieties on carbon nanotube surface. Subsequently, carboxylic acid moieties were submitted for amidation using TEMPO–NH2. The functionalized nanotubes [MWCNT‐{(CH2)3‐CO‐NH‐TEMPO}n] were investigated as a (pre‐)catalyst for the oxidation of primary and secondary alcohols for the production of aldehydes and ketones in a Montanari‐type catalytic oxidation using the cheap and readily available 1,3‐dichloro‐5,5‐dimethylhydantoin as the terminal oxidant.