Facile synthesis of Pd and Pt nanoparticles supported on the boron nitride nanotubes (Pd-BNNT and Pt-BNNT, respectively) for CO oxidation was explored. The reduction agent and stabilizer-free synthesis solely relies on the ultrasound treatment of the aqueous Pd2+ and Pt4+ precursors under the presence of BNNT. Reduction of Pd and Pt nanoparticles on the surface of BNNT was observed by means of the transmission electron microscopy and X-ray diffraction patterns. Quantitative analysis of Pd and Pt attached on the BNNT surface was also carried out using inductively coupled plasma atomic emission spectroscopy, showing that the concentration of metal nanoparticles on BNNT could be controlled by varying the initial concentration of metal precursors and the ultrasound treatment time. The morphological evolution of the nanoparticles on the surface of BNNT was observed by raising the temperature up to 800 degrees C in an air and up to 900 degrees C in vacuum. It was found that the nanoparticles were thermally stable up to 600 degrees C for both cases. The efficiency of catalytic oxidation of CO of the synthesized Pd-BNNT and Pt-BNNT was measured to be higher than similar to 98% at the temperature as low as similar to 125 and, similar to 150 degrees C, respectively.