A metal-free, facile, and efficient protocol for synthesizing a series of 2-alkenyl/alkynyl-5-nitropyridines was developed by using a three-component ring transformation of 1-methy1-3,5-dinitro-2-pyridone with alpha,beta-unsaturated ketones and ammonium acetate. As 2-alkenyl/alkynyl-5-nitropyridines are not easily prepared by the Heck or Sonogashira reactions, this method will be supplementary to these reactions.