N-Substituted dihydropyridines were converted into pyridinium salts with BF 3 OEt 2 as aromatization promoter in reactions that could be conducted without the need of the usually added oxidizing agents, such as quinones, nitrates, peroxides, and chromates. An optimization study employing an N-phenyl Hantzsch ester dihydropyridine (1a) to obtain the corresponding N-phenylpyridinium-containing ammonium quaternary salt (2a) was conducted to define the best conditions for the aromatization reaction: 3equiv of BF 3 OEt 2 at 0°C, in the dark, under atmospheric air in CH 2 Cl 2 to give yields up to 80%. These conditions could also be applied to additional examples of both N-substituted dihydropyridines and 1,4-dihydropyridines.