Pyridine is structurally similar to benzene, with a single nitrogen atom substituting in the six-member aromatic ring for one of the carbon and one of the hydrogen atoms.

Pyridine is a base. Its conjugate acid is a unipositive polyatomic ion called pyridinium, C₅H₅NH⁺.

Under conditions of standard temperature and pressure, pyridine is a liquid with a strong odor.