A glassy carbon electrode modified with palladium nanoparticles decorated multiwalled carbon nanotubes (GCE/nanoPd-MWCNTs) was fabricated. Incorporation of palladium nanoparticles onto the carbon nanotube surface by thermal decomposition of palladium acetate led to the fabrication of a sensor with a significant decrease in hydrazine electrooxidation potential. The sensor exhibited low detection limits, high sensitivity and selectivity, rapid response, and good stability toward hydrazine detection.