The gas phase UV absorption spectra of pyrazine, pyrimidine and pyridazine were determined by using a D2-lamp coupled to a monochromator-PM system between 200 and 380 nm, at 353 ± 3 K and at pressures lower than their vapor pressure (0.08–0.5 torr). The obtained spectra consist of a broad continuum with low intense absorption bands at 200–380 nm. Absorption of the investigated compounds at wavelengths>290 nm is non-negligible (σλ > 290 nm in the order of 10−20 cm2 molecule−1). These results indicate that, pyrazine, pyrimidine and pyridazine could be removed from the troposphere via photolysis reactions.